CMST Widebody Mustang Carbon Fibre Body Kit
The CMST widebody Mustang kit is a dry-carbon and FRP wide-arch aero package for the 2015-2017 (S550) Ford Mustang. It is one of the earliest and most complete widebody Mustang builds CMST produced, shown here on a competition-orange S550 with flared arches over all four corners, a vented carbon bonnet and a full set of carbon lower aero. The kit suits both the 2.3-litre EcoBoost and the 5.0 V8 GT, because the panels are shaped to the shared pre-facelift body rather than to a specific engine.
- Vehicle: Ford Mustang (S550), 2.3L EcoBoost and 5.0 V8 GT
- Fitment: 2015-2017 pre-facelift body (tri-bar tail lights, 2015-2017 grille)
- Material options: Dry/vacuum carbon fibre for show panels; FRP for the widebody arches and vented front fenders
- Key pieces: Front bumper with carbon lip and canards, carbon grille surround, carbon bonnet, vented FRP front fenders, four flared widebody arches, carbon side skirts and under-lip, carbon rear lip (two exhaust layouts), carbon rear wing
- Finish: Gloss twill-weave clearcoat on the carbon pieces; primed FRP arches and fenders ready for colour-matched paint
What the CMST widebody Mustang kit is
This is a complete aerodynamic and widebody conversion, not a single bolt-on styling part. CMST reworked the entire exterior of the S550: the front fascia, the bonnet, the guards, the sides and the tail all change together so the car reads as one design rather than a collection of add-ons. The lower aero and show panels are formed in dry carbon fibre, while the parts that need to flare out and carry body colour, the four wheel arches and the vented front fenders, are moulded in FRP. That split keeps the wider, more complex shapes affordable and easy to paint while reserving the visible carbon weave for the panels where it matters most.
Because the kit is shaped to the 2015-2017 body, it fits the four-cylinder 2.3 EcoBoost and the 5.0-litre V8 GT alike; the front and rear bumpers, bonnet and arches mount to the same pre-facelift sheet metal regardless of drivetrain. If you are mapping out a build, AME stocks the full CMST catalogue alongside the wider Ford Mustang body kit range so you can match parts to your car.
Piece-by-piece breakdown
Front bumper, lip and canards
The front end is the most reworked area of the car. CMST starts with an FRP front bumper and extends the centre grille line forward by roughly 3cm, which lengthens the nose and gives the face more presence. The fog-lamp area is restyled to delete the surplus factory lines, a carbon grille surround ties the opening together, and a large-angle carbon front lip wraps the lower edge. Carbon canards sit on the bumper corners. Functionally the lip reduces the volume of air slipping under the nose while the canards shed small vortices that trim front-axle lift, which steadies the front of a car that is otherwise prone to lift at speed. The carbon lip is also offered as a stand-alone piece in AME's CMST front lip for Ford listing if you want the front-end change before the full kit.
Carbon bonnet
CMST replaces the steel bonnet with a carbon item that carries more surface sculpting than the factory panel. Its signature is the central air outlet shaped like the Chinese character "ๅฑฑ", a three-peak vent flanked by two lightweight carbon vents. Beyond the look, those openings let hot air escape the engine bay, which matters on the supercharger-friendly 5.0 GT and on a hard-worked EcoBoost alike, and carbon removes mass from the highest, most forward panel on the car where shedding weight helps the front end turn. As with any aftermarket carbon bonnet, the factory latch or aftermarket bonnet pins should be checked for secure engagement before the car is driven. The panel is listed on its own as the CMST carbon bonnet for Ford.
Widebody arches and vented fenders
The widebody treatment is what sets this build apart. CMST supplies four flared arches as a front pair and a rear pair, each a multi-piece FRP set, that bolt and bond over the factory guards to add width across all four corners. They pair with vented FRP front fenders (ๅผๅญๅถๅญๆฟ) whose openings vent pressure out of the front wheel wells and visually break up the long flank of the Mustang. FRP is the right choice here: fibreglass forms the deep, compound arch curves more economically than autoclaved carbon, and the arches are painted to body colour anyway, so a carbon weave would never be seen. Fitting the flares is the part of the build that most often needs guard rolling or trimming of the OEM metal, depending on the final wheel offset and tyre width.
Side skirts
Along the flanks, CMST fits carbon side skirts that extend slightly outward from the factory rocker, with a separate carbon side-skirt under-lip beneath them. The skirts visually drop the car's centre of gravity to match the new arch width, smooth airflow down the side of the car between the front and rear wheels, and close the gap between the widened front and rear arches so the body looks continuous rather than pinched in the middle. The outward extension is deliberate: a standard-width skirt would look lost under the flared guards.
Rear lip and diffuser
At the tail, a carbon rear lip wraps the lower bumper and gives the back of the car a diffuser-style finish that visually pulls it towards the road. CMST offers the rear lip in two layouts: a dual-single-exit version and a dual-dual-exit version, so the panel can be matched to either a twin-tip or a quad-tip exhaust. Choosing the rear lip to suit your exhaust tips keeps the cut-outs tight around the pipes instead of leaving oversized gaps, which is the detail that separates a clean rear end from an afterthought.
Rear wing
A carbon rear wing finishes the kit. This is a high, GT-style wing rather than a subtle ducktail, so it sits up in cleaner air above the boot where it can do useful work. The payoff is added rear downforce, which matters most as speed builds: it loads the rear axle, helps balance the front lip and canards, and keeps a rear-drive Mustang from feeling light at the back. CMST forms it in carbon to keep the weight hanging off the bootlid low. The same wing is listed separately as the CMST rear wing for Ford for owners building in stages.
Dry carbon vs FRP vs the factory bumpers
The kit deliberately mixes two aftermarket materials, and the factory parts are a third. Knowing how each is made sets the right expectations on weight, finish and care.
| Material | How it is made | Strengths | Trade-offs |
|---|---|---|---|
| Dry carbon fibre | Pre-preg carbon cured under heat and vacuum/pressure, often autoclaved | Lightest and stiffest option; true twill weave show finish on bonnet, lip, skirts, rear lip and wing | Clearcoat is UV-sensitive and needs care; highest cost |
| FRP (fibreglass) | Glass fibre laid into a mould with resin | Robust, easy to paint, forms the deep widebody arch and fender shapes economically | Heavier than carbon; must be painted to look finished |
| PP (factory) | Injection-moulded polypropylene | Flexible, cheap, shrugs off minor knocks and kerb taps | Heavier, no weave finish, and not a performance or weight upgrade |
The practical takeaway is that CMST puts dry carbon where light weight and a visible weave earn their keep, the bonnet, lip, grille surround, side skirts, rear lip and wing, and uses FRP for the four arches and the vented fenders, where the panels are colour-matched and the curves are deep. The factory PP bumpers stay flexible and cheap, but they add weight without adding capability, which is the gap this kit is built to fill.
The demo car: wheels, suspension, brakes and exhaust
The orange demonstrator shows how the kit is meant to sit. It runs Concept One five-spoke wheels in 20-inch, staggered 9J front and 10J rear at ET40, wrapped in 255/35R20 front and 285/30R20 rear tyres to fill the widened arches. SF coilovers drop the car to close the guard gap and set the stance the flares were designed around. Behind the wheels are big brakes, an eight-piston 380mm setup at the front and Brembo F50 four-piston calipers on 362mm discs at the rear, which is a sensible match for a widebody Mustang carrying more grip.
The exhaust is a CMST dual-dual-exit valved system in 304 stainless steel with a brushed surface finish, chosen so its quad tips line up with the dual-dual-exit carbon rear lip. CMST states the system is lighter than the stock exhaust and flows more freely; the valves let it stay civil at cruise and open up under load. If you are pricing the exhaust on its own, it sits under AME's CMST cat-back exhaust for Ford listing. Treat the wheel, suspension, brake and exhaust choices here as the demo car's specification rather than a fixed part of the body kit; the aero panels fit independently of them.
Why carbon and a widebody suit the S550 Mustang
The S550 is a long, heavy, rear-drive coupe with plenty of front overhang, so it responds well to two things: shedding weight high and forward, and adding mechanical grip with a wider footprint. A dry-carbon bonnet, lip, skirts, rear lip and wing take mass off the extremities and add aero balance, while the FRP widebody arches let the car run the wider, more planted track that a 285-section rear tyre needs. There is a design payoff too. The factory Mustang shape is handsome but narrow over its wheels; flared arches, a vented bonnet and a GT wing give it the wide, purposeful stance that matches the car's muscle-car character without looking bolted on.
Frequently asked questions
Does the CMST widebody kit fit my Mustang year and engine?
The kit is shaped to the 2015-2017 (S550) Ford Mustang with the pre-facelift body, the one with the 2015-2017 grille and tri-bar tail lights. It fits both the 2.3-litre EcoBoost and the 5.0 V8 GT, because the bumpers, bonnet and arches mount to the same body panels regardless of engine. If your car is a 2018-onward facelift, the front and rear fascia differ and this kit is not the correct fitment.
Do the widebody arches need cutting or guard rolling?
Often, yes. The four flared arches are designed to cover a wider track and wider tyres, so depending on your final wheel offset, tyre width and ride height, some trimming or rolling of the factory guard lip can be needed to clear the tyre through full suspension travel and steering lock. Confirm your wheel and tyre package first, then have the arches fitted by a workshop that has done widebody conversions before.
What is the difference between the dry-carbon and FRP pieces?
Dry carbon fibre is pre-preg carbon cured under heat and vacuum or pressure: it is the lightest and stiffest option and shows a real twill weave under clearcoat. CMST uses it for the bonnet, front lip, grille surround, side skirts, rear lip and rear wing. FRP (fibreglass-reinforced plastic) is heavier but forms the deep widebody arch and vented-fender shapes more economically and takes paint well, so it is used for the four arches and the front fenders, which are colour-matched to the body.
Does the kit need professional fitment?
Yes. Carbon and FRP panels are more brittle and far less forgiving than the flexible factory PP bumpers, and the widebody arches, vented fenders and lower aero all need careful trial-fitting, secure mounting and colour-matched paint. A body shop will set the panel gaps, paint the FRP to match your colour and sort tyre clearance on the arches, which is the work that gives the kit its flush, factory-grade result.
Can I buy individual pieces or build it in stages?
Yes. The kit is made up of discrete components, the front bumper and lip, canards, grille surround, bonnet, fenders, arches, side skirts, rear lip and wing, so you can stage the build rather than buying everything at once. A common path is to start with the carbon front lip and bonnet for the front-end change, then add the widebody arches and rear aero later. Contact AME Motorsport to confirm current availability of single pieces for your S550.
Build your widebody Mustang with AME Motorsport
If you are planning a carbon widebody for a 2015-2017 S550 Ford Mustang, AME Motorsport can supply the CMST panels and help you stage the build around your painter, your wheel and tyre package and your workshop. Start with the CMST body kit for Ford range to see the carbon and FRP components, then get in touch to confirm fitment for your EcoBoost or 5.0 GT.