Planning a widebody S550 starts with the finished car you want to build. Before ordering panels, match the kit to your Mustang, plan the wheels and talk through the installation.
A real S550 in the SHIROKAI Army
@the_eco_snake owns a completed SHIROKAI S550 in Rowland Heights, California. His first SHIROKAI purchase was a spoiler. Later, he bought a Mustang that already had the full kit installed.
That makes this an owner feature, rather than an installation diary. We have not confirmed the car's exact wheel offsets, suspension settings or original installer, so the photos should not be used as a wheel-fitment specification.
Which S550 kit fits your Mustang?
The 2015–2017 and 2018–2023 Mustangs use different front sections. Choose the kit for your car's model year, and check your trim and bumper before ordering:
If your car has a replacement bumper, tell us which one. Convertible owners should check the spoiler compatibility separately; the product page includes a configuration without the ducktail.
What comes with the kit?
The S550 kit includes front and rear flares, side skirts, bumper endings and a front lip. The ducktail comes with the full-kit-with-spoiler configuration. Mounting hardware is sold separately. Check the selected configuration and current price on the product page.
Plan the wheels with the bodywork
The flares add 90 mm per side at the front and 110 mm per side at the rear: 180 mm and 220 mm across the respective axles. Those measurements describe the body panels. They do not specify a wheel offset.
Wheel width, offset, tire size, ride height, suspension and brake clearance need to work together. Use the wheel fitment calculator as a starting point, then have your installer verify the setup on your car before buying wheels.
For a useful fitment conversation, send your model year, trim, bumper, current wheel and tire sizes, suspension setup and the look you want. A photograph of the car also helps.
Budget for the finished car
The kit price is one part of the build. Ask your shop for a written estimate covering test fitting, bodywork, mounting hardware, finishing and installation. Plan wheels and tires separately, and include shipping and any applicable local charges.
There is no single installation price that applies to every S550. Paint, wrap, existing modifications and the condition of the car can change the work involved. Agree on the scope before booking the job.
What should you confirm before ordering?
- The correct kit generation and bumper compatibility.
- Whether you want the ducktail configuration.
- Your proposed wheels, tires and suspension.
- Who will install and finish the panels.
- The total delivered price and current dispatch information for your order.
Need help putting those details together? Email i@shirok.ai with your Mustang's year, trim and delivery country. Tell us what you would like to check: fitment, wheels or installation.