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The CMST widebody kit for the Mercedes-Benz CLA (C118) turns the four-door coupe into a full widebody build using carbon-fibre and FRP aero, fitted here to a CLA 250 4MATIC in red. It is a complete package — two-piece carbon front lip, carbon rear lip with square exhaust cut-outs, FRP side skirts, a vented carbon bonnet, six-piece FRP wheel arches front and rear (with a pair of carbon canards), and a large carbon rear wing — designed to widen the stance rather than just add trim. This feature breaks down every piece, the carbon-versus-FRP material split, and how the kit fits.

• Vehicle: Mercedes-Benz CLA, C118 generation (CLA 250 / CLA 200 / CLA 35-45 AMG)
• Style: Full widebody aero kit with bolt-on arch extensions
• Carbon pieces: Two-piece front lip, rear lip (square tips), vented bonnet, canards, rear wing
• FRP pieces: Side skirts, front wheel arches (6-piece), rear wheel arches (6-piece)
• Matching parts shown: SUS304 valved mid-and-rear exhaust, two-piece 19-inch forged wheels

The C118 CLA is one of Mercedes' most rakish small cars, and CMST's argument is that a few stick-on trims do not do it justice — to change the proportions you have to go wide. Here is how the kit is put together.

Piece-by-piece: the CMST CLA widebody kit

Two-piece carbon front lip

The front lip is a two-piece dry-carbon design. Stacking two blades creates a double-deck carbon layer at the nose, which gives the front a deeper, more planted face and a clear horizontal shadow line. On a low car like the CLA the lip also adds front-end air management and takes the first hit from speed humps and driveways before the painted bumper does.

Vented carbon bonnet

The bonnet is carbon fibre with a vented, sculpted top surface. Beyond the visual, the cut-outs help release heat from the engine bay and the carbon panel removes weight from the nose — the most useful place to lose it on a front-drive-based platform. The pressed lines give the flat bonnet some shape that the standard panel lacks.

FRP side skirts and six-piece wheel arches

The side skirts and the front and rear wheel arches (six pieces each) are moulded in FRP — fibreglass-reinforced plastic. FRP is the right call for the arches: they are large, body-coloured panels, and FRP paints to match the car so the widebody reads as one continuous shape rather than a bolt-on. The arches are what actually widen the CLA, giving clearance for a wider wheel-and-tyre package and squaring off the haunches.

Carbon canards

Paired with the front arches is a set of carbon canards (风刀, "wind blades") that mount to the front corners. They add a motorsport-style detail to the bumper edges and break up the visual mass of the widened front guards. These are exposed carbon, so they contrast against the painted arches.

Rear lip, rear arches and rear wing

At the back, a carbon rear lip with square exhaust cut-outs frames the tips and is shaped to suit the wider rear arches. The oversized carbon rear wing is the kit's signature — it lifts the tail visually and gives the CLA a genuine fastback-racer outline. Together with the rear arches, the back of the car gains the same width as the front so the stance stays balanced from every angle.

Exhaust and forged wheels shown on this build

This CLA also runs a CMST valved mid-and-rear exhaust in SUS304 stainless with a brushed finish and a larger-than-stock pipe diameter, plus a set of two-piece 19-inch forged wheels. The valved exhaust keeps the car quiet on light throttle and opens up under load, while the larger bore helps flow during hard driving without killing low-down response. The two-piece forged wheels fill the new arches and are a structural part of making a widebody look finished. Both are sold separately from the body kit.

Carbon fibre or FRP: how CMST splits the materials

This kit is a good case study in mixing materials sensibly. Carbon fibre is used where the weave is meant to be seen and where light weight matters — the lip, bonnet, canards, rear lip and wing. FRP is used for the big body-coloured panels — skirts and arches — because those parts are meant to disappear into the paint, and FRP is cheaper to produce in large, complex shapes and takes paint readily. The result is exposed carbon at the aggressive details and seamless body colour across the width.

If you are speccing your own car, you can keep the same split or go all-carbon on the accents. Browse the full CMST body kit range for Mercedes-Benz, compare wing and spoiler options in the CMST spoiler collection, and see finish choices across the wider carbon fibre body kit range.

Wheels and tyres for the widebody

A widebody lives or dies on its wheel fitment, so it is worth planning before the arches go on. The point of the flares is to cover a wider, more aggressive wheel-and-tyre package than the standard car can run, and getting that package right is what makes the build look poured-in rather than gappy. The two numbers that matter are width and offset: a wider rim with a lower (more negative) offset pushes the wheel face outward to meet the new arch line. This build uses two-piece 19-inch forged wheels, which suit the CLA because a two-piece design lets the barrel width and offset be specified to the car rather than bought off the shelf. Tyre choice follows — a stretched or flush setup changes how the shoulder sits under the flare. Because the C118 is based on a front-drive platform, front clearance at full steering lock is the tightest constraint, so a fitment check on a hoist before final torque is essential. Your installer will confirm the offset, tyre size and any spacer needed so the car clears on compression and at full lock without rubbing the liner or the new arch.

Fitment and finish

The kit is model-specific to the C118 CLA, so the arches and lips locate to the factory body lines. A widebody is a more involved fit than a simple lip kit: the arch sections need careful alignment, body-colour painting, and a wheel-and-tyre package chosen to fill the new width without rubbing. We recommend professional fitment and a proper wheel fitment check (offset and tyre size) so the car sits flush and clears at full lock and on compression. Carbon parts come clear-coated; FRP arrives in primer ready for paint. Budget for paint and fitment when costing a widebody, as the arch painting and wheel package are a real part of the spend, not an afterthought.

Frequently asked questions

Does the CMST CLA kit fit the AMG CLA 35 and CLA 45?

It is built for the C118 CLA body, which the CLA 35 and CLA 45 share, but the AMG cars use a different front bumper, so confirm your exact trim and bumper when ordering the front lip and arch sections.

Is this a true widebody, or just arch trims?

It is a true widebody — the six-piece front and rear arch sections extend the guards to cover a wider wheel-and-tyre package, not just decorative add-ons over the standard arches.

Why are the skirts and arches FRP instead of carbon?

Those are large, body-coloured panels meant to blend into the paint. FRP is easier to mould in big complex shapes, takes paint cleanly, and keeps the cost sensible. The pieces meant to show their weave — lip, bonnet, canards, wing — are carbon.

What wheels do I need for the widebody?

You will need a wider, more aggressive offset than standard to fill the arches. This build uses two-piece 19-inch forged wheels; your installer can confirm the right offset and tyre size for your ride height.

Can I buy the front lip or rear wing on their own?

Yes. Every piece is available individually, so you can start with the carbon front lip or the rear wing and add the widebody arches later.

Build your CLA

To plan a CLA widebody for Australian roads, start with the CMST Mercedes-Benz body kit collection and talk to the team through the CMST collection. We will help you match the carbon and FRP pieces, choose a wheel package, and sort painting and fitment locally.