Mustang Widebody Kit 2018-2023 GT S550 SHIROKAI

$5,490.00
Shipping calculated at checkout.
Full kit with ducktail spoiler
Estimated shipping:
🇺🇸 USA: approx $600
🇪🇺 Europe: approx €400
🌍 Other regions: calculated at checkout
Exact total calculated at checkout
  • Full kit with ducktail spoiler
  • Kit without spoiler

Pay your way — upfront or over time.*
Widebody Ford Mustang with custom body kit and aggressive front bumper on white background Widebody Ford Mustang with custom body kit and aggressive front bumper on white background
Mustang Widebody Kit | 2018-2023 GT S550 | SHIROKAI
$5,490.00
Full kit with ducktail spoiler

Complete widebody conversion for the 2018–2023 Ford Mustang S550. Vehicle-specific ABS panels engineered from 3D scans, adding up to 4.33 in (110 mm) per side while preserving the facelift Mustang's original body lines.


   

Anyone can make a car wider.
Very few can make it right.

Before you notice the details, your brain decides how a car feels.

SHIROKAI

SHIROKAI

FACTORY

FACTORY

THE CLOSER YOU LOOK, THE MORE IT SHOULD MAKE SENSE.

WHAT YOU FELL FOR SHOULD MAKE IT TO YOUR GARAGE.

SHIROKAI design and production process
SHIROKAI widebody kit laid out before installation
NOW IT'S YOUR TURN.

Every SHIROKAI build starts with this photo.

Open the box. Lay every panel around the car. Take a step back. That photo is the first memory of your build.

THE REST IS YOUR STORY.

Overall the kit has been one of the best fitting kits I've worked with.

@ultrasrt · Challenger

Gotta love when people are snapping pics of this thing!

@halliday_built

Short gas station stop ended up with 2 hours filming and 5M+ views reel

@nkognndo2112 · Challenger

I still look back every time I park.

@timon_lacoste · Mustang S197

EVERYTHING YOU NEED BEFORE ORDERING

Everything below answers the questions that usually come up once you've already decided this is the kit you want.

  • QUICK SPECS

    Included

    Front fender flares, rear fender flares, side skirts, bumper endings, front lip spoiler and rear ducktail spoiler.

    Material

    Automotive-grade ABS plastic, CNC-cut from vehicle-specific 3D scan data. Black in mass, wrap-ready. Light sanding and primer recommended before paint.

    Added Width

    Front: +3.54 in (90 mm) per side.

    Rear: +4.33 in (110 mm) per side.

  • Wheel Fitment

    very SHIROKAI widebody is designed around a significantly wider wheel and tire setup.

    Exact specifications depend on ride height, suspension, brake package and the look you're after.

    Use our Wheel Fitment Calculator to find a recommended starting point for your build.

    p.s. No you can't use your factory wheels with spacers, you will need 80-120mm spacers and it's just unsafe for public roads.

  • Installation

    Professional installation is recommended.

    SHIROKAI INSTALLERS - FIND YOUR LOCAL SHOP

    DIY installation approved.

    SHIROKAI panels arrive CNC-trimmed and developed from 3D scans of the original body, reducing unnecessary fabrication compared to universal or cheap fiberglass kits.

    Ready to wrap out of the box.

    Standard body shop preparation such as drilling, sanding, primer and paint should still be expected.

    Every build is slightly different. A skilled installer will always achieve the best result.

  • Shipping

    Every kit is carefully inspected before shipping and securely packaged for international transport.

    Once dispatched, you'll receive tracking information.

    For US customers Import fees available to be paid upfront, check for the option at the checkout. (10% paid upfront or up to 15% paid on delivery)

    Import duties and local taxes, if applicable, are determined by your country's customs regulations.

  • Didn't find your answer?

    Browse our complete FAQ → or send us a message, we're happy to help!

FITMENT GUIDE

Check your exact year and trim before ordering.

Years Trim Fitment Notes
2018–2023 Mustang GT ✅ Direct fit Developed specifically for GT models
2018–2023 Mustang EcoBoost ✅ Direct fit Direct fit with the factory bumper
2018–2023 Mustang Convertible ⚠️ Partial fit Kit fits, but the ducktail spoiler is excluded due to the different trunk lid
2018–2020 Shelby GT350 & non-GT bumpers 🔧 Modifications required Minor front bumper modifications required
2015–2017 Mustang S550 Pre-Facelift ❌ Different kit Uses a different front fascia and requires the pre-facelift version
2005–2014 Mustang S197 ❌ Different kit Designed for a different Mustang generation
2018–2023
✅ Direct fit
Mustang GT
Developed specifically for GT models
2018–2023
✅ Direct fit
Mustang EcoBoost
Direct fit with the factory bumper
2018–2023
⚠️ Partial fit
Mustang Convertible
Kit fits, but the ducktail spoiler is excluded due to the different trunk lid
Configure without spoiler
2018–2020
🔧 Modifications required
Shelby GT350 & non-GT bumpers
Minor front bumper modifications required
2015–2017
❌ Different kit
Mustang S550 Pre-Facelift
Uses a different front fascia and requires the pre-facelift version
View 2015–2017 Kit

TECHNICAL DOCUMENTATION

Complete specifications, compatibility notes and additional product information.

VIEW COMPLETE TECHNICAL DOCUMENTATION HIDE TECHNICAL DOCUMENTATION

The SHIROKAI 2018–2023 Mustang S550 Widebody Kit is engineered for the facelift Ford Mustang S550 platform, giving GT and EcoBoost builds a wider stance, stronger side profile, and more room for an aggressive wheel and tire setup — while still following the factory body lines.

This is not just an overfender kit. Each SHIROKAI Mustang S550 widebody kit is CNC-cut from platform-specific 3D scan data for cleaner fitment, better proportions, and less fabrication drama during installation. Made from premium automotive ABS plastic, it brings the Kaiju feeling without turning the car into a random bolt-on mess.

Ford Mustang S550 (2018-2023) Widebody Kit — Quick Facts

  • Fits: 2018–2023 Mustang GT and EcoBoost (plug-and-play), Convertible kit-only (spoiler excluded), 2018–2020 Shelby GT350 with minor bumper mods
  • Material: Automotive-grade ABS plastic, 3D-scanned and CNC-cut from OEM body
  • Width added: +3.54 in (9 cm) per side front, +4.33 in (11 cm) per side rear — 220 mm total added width
  • Install: 12–16 hours at a body shop, plug-and-play for 2018–2023 GT/EcoBoost with stock bumper
  • Includes: Front flares, rear flares, side skirts, bumper endings, front lip spoiler, rear ducktail spoiler
  • Price: $4,500 USD (full kit with spoiler) — designed for the redesigned 2018+ S550 front fascia
  • Designed for: Post-facelift S550 with redesigned hood, headlights, and front bumper geometry
  • Shipping: Worldwide via UPS, ~$600 to USA, ~€400 to Europe, tracked

What’s in the Ford Mustang S550 Widebody Kit

  • Front fender flares
  • Rear fender flares
  • Side skirts
  • Bumper fender endings
  • Front lip spoiler
  • Rear trunk spoiler

Width & Specs

Front fenders add 3.54 in (9 cm) per side, rear fenders add 4.33 in (11 cm) per side, measured from the stock arch — run wider wheels and tires for more grip on road and track.

  • High-grade automotive ABS plastic
  • Black in mass — wrappable straight out of the box (light sanding + primer recommended for best paint result)
  • Easy plug-and-play fit, no major bodywork needed

Ford Mustang S550 Widebody Kit Fitment Guide (2018–2023)

Confirmed fitment for 2018, 2019, 2020, 2021, 2022 and 2023 Ford Mustang:

Year Model Fitment Notes
2018–2023 Mustang GT ✅ Plug & Play Direct fit, no modifications needed
2018–2023 Mustang EcoBoost ✅ Plug & Play Direct fit, no modifications needed
2018–2023 Mustang Convertible ⚠️ Partial fit Kit fits, ducktail spoiler excluded (different trunk lid)
2018–2020 Shelby GT350 & non-GT bumpers 🔧 With modifications Minor front bumper modifications required
2015–2017 Mustang S550 pre-facelift ❌ Different kit See the S550 2015–2017 kit →
2005–2014 Mustang S197 ❌ Different kit See the S197 widebody kit →

Not sure about your trim? Email i@shirok.ai — we confirm fitment within 24h.

Why S550 Owners Love It

All you need is steady hands, a heat gun, and some cut-and-sand instrumentals. With a growing community of SHIROKAI Mustang owners, this S550 kit became an absolute best seller and delivered strong results. If there’s a Mustang with a SHIROKAI kit at a show, it gets attention and love. Fitment is one of the biggest strengths of this wide body S550 setup — SHIROKAI is known for parts that fit straight out of the box, so you spend less time in the shop and more time driving. Whether you search for a mustang widebody, a mustang wide body build, or an S550 body kit, this keeps clean bodylines with a bold, planted look.

Wheels & Tires

Dial in your exact setup with our Widebody Wheel Fitment Calculator.

Finishing

Want to test our quality first? The ducktail spoiler is included in the full kit, and also sold separately — same ABS material, same fitment standard, fits 2015–2022 S550 trunk lids. See the S550 Ducktail Spoiler →

Technical Specifications

Spec Detail
Material Automotive-grade ABS plastic
Manufacturing CNC-cut from OEM 3D scan data
Front flare width +3.54 in / +9 cm per side
Rear flare width +4.33 in / +11 cm per side
Total added width 220 mm across both axles
Components 6-piece kit: front flares (2), rear flares (2), side skirts (2), bumper endings, front lip spoiler, ducktail spoiler
Mounting Bolt-on with included hardware, drilling and rivnuts required
Install time 12–16 hours at a body shop
Paint prep Light sanding + primer recommended for best finish
Wrap compatibility Yes, surface ready out of the box
Compatible vehicles 2018–2023 Mustang GT/EcoBoost (plug-and-play), Convertible (kit-only), 2018–2020 GT350 (with mods)
Body generation S550 facelift (post-2018 redesigned front fascia)
Country of manufacture Turkey (Bursa)
Support Lifetime tech support from manufacturer

For best results, professional installation is recommended. The finish wraps from the box (light sanding + primer for paint). Every Ford Mustang S550 widebody kit is built for style, function, and quality — the bold flares and precise fit take your Mustang to the next level.

Frequently Asked Questions

Will this kit work on my Mustang Convertible?

Partially. The flares, side skirts, lip, and bumper endings all fit a 2018–2023 Convertible identically to the Coupe. However, the ducktail spoiler is excluded — Convertibles use a different trunk lid geometry that the spoiler doesn't match. Convertible owners typically order the kit without the ducktail spoiler option at checkout.

What about Shelby GT350 fitment?

The GT350 (produced 2018–2020) uses a different front bumper than the standard GT. The kit fits with minor front bumper modifications — typically light trim work to mate the bumper endings cleanly with the flares. A competent body shop handles this in 1–2 extra hours during install. All other panels (flares, skirts, spoiler) fit identically to the GT. Note: GT350 production ended in 2020 — for 2020+ Mustangs above the GT, the GT500 uses a substantially different front-end and is not covered by this kit.

Is this kit different from the 2015–2017 S550 kit?

Yes. The 2018 facelift Mustang received a redesigned hood, headlights, and front fascia — so the kit requires a different front-section design. The actual flare and skirt dimensions are identical between the two S550 kits (220 mm total added width), but the bumper endings and front lip are platform-specific. If you have a 2015–2017, see our S550 2015–2017 widebody kit.

How does the width compare to other SHIROKAI Mustang kits?

This S550 kit adds 220 mm of total width (9 cm front + 11 cm rear per side). Our S197 kits add 240 mm total (9 cm front + 12 cm rear per side). The slightly narrower S550 stance is intentional — it follows the S550's tighter factory body lines for a cleaner, OEM+ aggressive look rather than maximum-width drama. Both generations share the same 9 cm front-fender addition.

How long does installation take?

Typical body shop install runs 12 to 16 hours including test fit, drilling, and rivnut setup. The install requires drilling holes in the fender for rivnut-mounted flares — this is standard procedure for properly secured aftermarket widebody and shouldn't be attempted without the right tools.

Will my doors still open with the flares installed?

Yes. The flares follow the factory door cutline. Both doors remain fully operable at any opening angle. The kit does not interfere with door handles, mirrors, or fuel filler door operation.

What wheel and tire setup works with this kit?

220 mm of total added width supports significantly wider wheel and tire setups than stock — typically 19x11 or 20x11 wheels with 295–315 mm tires in the rear, and 19x10 with 275–285 mm tires up front depending on offset preference. Use our Widebody Wheel Fitment Calculator for precise sizing tailored to this kit.

You may also like

Ready out of the box

FAST WORLDWIDE DELIVERY

Lifetime support

PRIVATE MEMBERS CLUB

SHIROKAI gift card widebody certificate showing a split image of a red and black widebody muscle car SHIROKAI gift card widebody certificate showing a split image of a red and black widebody muscle car

If something left unanswered, don't hesitate to drop a message

   
* Pay-over-time options vary by customer and are subject to eligibility and provider approval.