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This is a complete CMST widebody build on an Audi TT: a mixed FRP-and-carbon body conversion, a SUS304 stainless valved cat-back exhaust with carbon tips, and a set of two-piece forged wheels. The TT's rounded, almost soft factory shape is the starting point; the widebody arches, carbon aero and aggressive wheel package turn it into something far harder-edged. It is a worked example of how three upgrade categories — body, exhaust and wheels — come together on one car, and a useful reference for owners planning a similar TT build.

• Vehicle: Audi TT (earlier-generation coupe in this build)
• Body material: FRP front bumper, fenders and arches; carbon fibre lip, rear lip, skirts; bonnet offered in FRP or carbon
• Exhaust: SUS304 stainless valved cat-back, dual-exit, carbon tips
• Wheels: Two-piece forged, brushed finish, deep concave
• Key body pieces: Front bumper, front lip, rear lip (quad-exit), side skirts, fenders, front and rear arches, bonnet
• Stance: Widebody — wider track, flared arches, deep-dish wheels

The TT was designed as a style object first and a sports car second, which is why it responds so dramatically to a widebody. Sharpen those round shoulders and the whole character changes. This build does it across three fronts at once — here is how each part contributes.

The widebody: from round to resolved

The body conversion is the foundation. CMST replaces the factory front bumper with an FRP unit and adds a carbon front lip that pushes the leading edge forward — the source notes it "protrudes slightly forward," which is the detail that breaks the TT's rounded nose and gives it a flatter, more planted face. FRP fenders and front and rear wheel arches widen the body so it can carry a much wider wheel and tyre package, while carbon side-skirt under-lips tie the widened front and rear together along the sill.

At the rear, a carbon rear lip wraps around the bumper with its edges hooked upward — that wrap-around shape is what makes the widebody look intentional rather than bolted-on, visually pulling the wider rear quarters together. The lip is built around a quad-exit exhaust layout, which sets up the next part of the build. The bonnet is offered in either FRP or carbon depending on whether you prioritise cost or weight saving over the front axle.

The exhaust: SUS304 valved cat-back

The exhaust is a CMST dual-exit valved cat-back built from international-standard SUS304 stainless steel with a brushed finish. SUS304 is the grade that matters here: it resists the corrosion and heat-cycling that kill cheaper mild-steel systems, so the exhaust stays clean and intact through years of Australian weather and hard driving. The fabrication uses fine "fish-scale" TIG welds — the closely-stacked bead pattern that signals a properly hand-welded system rather than a mass-produced one.

The headline feature is the electronically controlled valve. A remote opens and closes the valve to change the exhaust note on demand: closed for a civil commute, open for a deep, full-bodied roar when you want it. That flexibility is what makes a valved system worth the premium — one car that can be quiet in a carpark at night and loud on a back road. The system is finished with carbon tailpipe tips to match the carbon aero. For the construction and sound details of the matching system, see the CMST cat-back exhaust range.

The wheels: two-piece forged

The build is finished on a set of two-piece forged wheels in a brushed finish with a deep concave face. The construction is the important part: a two-piece forged wheel is built from a separately forged centre and rim bolted together, which lets the offset and dish be tailored to fill the new widebody arches exactly — something a one-piece cast wheel cannot match. Forging also produces a denser, stronger structure than casting, so the wheels can be lighter for a given strength, trimming unsprung mass and sharpening the way the TT changes direction.

The deep-dish face and the flared arches were designed to work together: the extra arch clearance from the widebody is what allows the aggressive wheel fitment, and the wheels are what fill that clearance. If you are planning your own build, the CMST forged wheel range and the broader forged and carbon wheel collection show the construction options for matching a wheel package to a widebody.

How the build comes together

What makes this TT work is that the three upgrades reinforce one another rather than competing. The widebody creates the arch clearance; the forged wheels fill it; the carbon aero and carbon exhaust tips share a visual language front to back. Take any one element away and the car looks unbalanced — the widebody without the wheels looks empty in the arches, the wheels without the widebody would foul the bodywork. Planned together, they read as a single coherent design.

A few build notes for anyone replicating it. The FRP body panels arrive in primer and need painting to match — factor paint into the budget. The widebody track change means alignment and clearance should be checked after fitting, through full suspension travel and steering lock. And the carbon pieces and tips should be sealed and maintained like paint to keep the lacquer clear under strong sun.

This CMST Audi TT build combines a widebody body conversion (FRP bumper, fenders and arches with carbon lip, rear lip and skirts), a SUS304 valved cat-back exhaust with carbon tips, and two-piece forged wheels with a deep concave face — three upgrade categories planned to work as one.

Frequently asked questions

What does the CMST TT widebody kit include?

The body conversion comprises an FRP front bumper, a carbon front lip, a carbon rear lip built for a quad-exit exhaust, carbon side-skirt under-lips, FRP front fenders, and FRP front and rear wheel arches. The bonnet is offered in either FRP or carbon fibre. It is a full widebody, not a bolt-on lip kit.

What is the exhaust made from, and how loud is it?

The cat-back is built from SUS304 stainless steel with a brushed finish and carbon tips. It uses an electronically controlled valve operated by remote, so you can switch between a quiet, civil note with the valve closed and a deep, full roar with it open. SUS304 resists the corrosion and heat-cycling that shorten the life of mild-steel systems.

Why two-piece forged wheels instead of cast?

A two-piece forged wheel has a separately forged centre and rim, so the offset and dish can be tailored to fill widebody arches exactly. Forging also yields a stronger, denser structure than casting, allowing a lighter wheel for a given strength, which reduces unsprung mass and sharpens steering response.

Can I fit the widebody without changing wheels?

You can fit the body panels alone, but a widebody creates extra arch clearance that standard wheels will not fill, so the car can look empty in the arches. The widebody and a wider wheel package are designed to work together; plan the wheel fitment as part of the build rather than as an afterthought.

Will the FRP body panels arrive painted?

No. The FRP bumper, fenders and arches are supplied in primer and are painted to match your car during fitment. The carbon pieces and exhaust tips arrive in a lacquered weave and are not painted over.

Does fitting a widebody affect alignment?

Widening the track and changing the wheel fitment means the alignment and arch clearance should be checked after the build, through full suspension travel and steering lock, so the tyres clear the arches and the car tracks correctly.

Planning a TT build of your own? Explore the CMST forged wheel range, the CMST cat-back exhaust range, or the wider forged and carbon wheel collection at AME Motorsport, and talk to our team about staging a full widebody build in Australia.