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The CMST BMW i4 kit is a full dry carbon-fibre aero package — front lip, four-piece bumper canards, side skirts, rear lip and a rear spoiler — designed for the i4 Gran Coupe, including the i4 M50. Every exterior piece is dry carbon (autoclave-cured pre-preg), so the kit adds genuine carbon hardware rather than a wrap, and the weave reads consistently from the front splitter to the rear spoiler. It is shaped to the i4's four-door electric coupe body, which makes it a bolt-on match for the factory bumpers and boot lid, and it gives BMW's electric Gran Coupe a sharper, more aggressive stance without touching the silhouette.

• Vehicle: BMW i4 Gran Coupe (G26), including eDrive40 and i4 M50; 2021/2022 onward
• Material: Dry carbon fibre throughout (pre-preg, autoclave-cured)
• Key pieces: Front lip with corner sections, four-piece front bumper canards, two-piece add-on side skirts, rear lip, rear spoiler
• Finish: Gloss twill weave under clearcoat (suits the i4's Frozen and metallic paints)
• Design note: Flowing, swept rear spoiler profile; bolt-on/adhesive fitment to the standard body

What the CMST i4 kit is

The i4 is BMW's electric Gran Coupe — a sleek, four-door fastback that already looks premium, which is exactly why an all-carbon aero kit suits it. CMST took the single-material route here: every panel is dry carbon fibre, so the build keeps one consistent weave from the front lip to the rear spoiler rather than mixing materials. The kit is a clean set of bolt-on aero pieces — front lip, canards, side skirts, rear lip and spoiler — that sharpen the i4's lines and lower its visual ride height while leaving the factory bodywork in place. AME carries the full CMST catalogue alongside the wider BMW body kit range, so an i4 owner can fit the whole set or stage it over time.

Because the kit is all dry carbon, it is as much about material as shape: the gloss twill finish is the point, and it reads particularly well against the i4's Frozen (matte) and darker metallic paints. This is a styling-led carbon package — it adds presence, weave detailing and a lower, wider look. Treat the lip, canards and spoiler as visual and airflow-tidying upgrades rather than a claimed downforce figure.

Front end: carbon lip with corners and four canards

The front of the kit pairs a dry-carbon front lip with a four-piece set of carbon bumper canards. CMST shapes the lip with wrapped corner sections — a "bull-horn" style that curls the lip ends up into the bumper corners — so the splitter flows into the bodywork instead of stopping abruptly. The lip drops the leading edge of the i4's bumper and gives the nose a lower, more planted look, while the four canards sit on the bumper corners and add visual aggression and small airflow tidying down each flank. On the i4's large, closed-off electric front face, the carbon lip and twin-canard-per-side layout do a lot to break up the smooth bumper and give it intent. Browse the equivalent parts through AME's CMST front lip for BMW and CMST bumper for BMW collections.

Sides: carbon add-on skirts

Along the flanks, CMST supplies a two-piece set of dry-carbon add-on side skirts that bolt onto the lower edge of the i4's existing sills. Add-on skirts extend the rocker line and visually pull the car down towards the road, tidying the airflow between the wheels and tying the front lip into the rear. Because they are an add-on rather than a full skirt replacement, they keep installation straightforward and the factory sill intact. Against a matte or dark metallic i4, the gloss carbon along the lower body draws a clean horizontal line that makes the Gran Coupe look longer and lower. See the related CMST side skirts for BMW range.

Rear: carbon lip and a swept spoiler

At the back, a dry-carbon rear lip wraps the lower bumper to balance the front splitter and give the tail a planted, diffuser-style edge, framing the i4's rear and integrating with its existing reflector and bumper shape. Above it, CMST's rear spoiler uses a flowing, swept profile that follows the curve of the boot lid rather than standing up as a tall fixed wing — a design that suits the i4's elegant fastback roofline and adds a three-dimensional rear without looking out of place on an executive EV. The carbon weave on the spoiler is one of the most visible parts of the build, sitting right at eye level on the boot. For the spoiler and rear-lip options, AME lists the CMST spoiler for BMW and CMST diffuser for BMW collections.

Why dry carbon on an electric BMW

Dry carbon fibre is the premium choice for an i4 build for a few concrete reasons:

• Weave finish: Dry carbon shows a crisp 2x2 twill pattern under clearcoat, which is the visual point of the kit. On a Frozen-paint i4 the gloss weave contrasts beautifully with the matte body.
• Stiffness and weight: Autoclave-cured pre-preg carbon is lighter and stiffer than wet-layup carbon or FRP, so the aero pieces hold their shape and add minimal mass — a sensible consideration on an EV where range and weight matter.
• Consistency: Building every panel from the same material means the weave and sheen match from the front lip to the rear spoiler, which is what makes the i4 read as a coordinated build rather than a parts-bin collection.

The full dry-carbon range sits in AME's CMST carbon fibre body kit and CMST body kit for BMW collections.

Fitment and finish in Australia

The i4 kit is shaped for the factory body, so the pieces follow the car's lines and mount to the existing bumpers, sills and boot lid — but it is still a job for a proper fit-up. Each piece needs trial-fitting, panel-gap setting against the adjacent OEM panels, and secure mounting with the right mix of clips, bolts and panel-safe adhesive. The add-on skirts and rear spoiler rely on clean, properly prepared surfaces to bond reliably. Dry-carbon clearcoat is UV-sensitive, so on an Australian-garaged car it pays to wash with pH-neutral products and consider a UV-stable ceramic coating or PPF on the leading edges to keep the weave from yellowing and to guard against stone chips. AME can supply the CMST i4 pieces and advise on fitment; the full set sits in the CMST carbon fibre body kit and CMST body kit for BMW collections.

Frequently asked questions

Which BMW does the CMST i4 kit fit?

It is designed for the BMW i4 Gran Coupe (G26 platform), which covers the rear-drive eDrive40 and the dual-motor i4 M50 from the 2021/2022 model year onward. It is shaped to the i4 body, so confirm your car is an i4 Gran Coupe before ordering. The pieces are tailored to the i4's bumpers and are not designed for the petrol 4 Series Gran Coupe unless specified.

Is the kit dry carbon or wet carbon?

Every piece in this kit is dry carbon fibre — pre-preg carbon cured under heat and pressure in an autoclave. Dry carbon is lighter and stiffer than wet-layup carbon and carries a crisp 2x2 twill weave under clearcoat. CMST built this i4 kit as an all-dry-carbon set, which is why the weave matches across the front lip, canards, skirts, rear lip and spoiler.

Does the carbon kit affect the i4's range?

The effect is minimal. Dry carbon is light, so the aero pieces add very little weight, and external add-on parts do not change the drivetrain. Any real-world range difference from a styling kit like this is negligible compared with factors such as wheel-and-tyre choice, driving style and climate, so the kit is fitted for looks and stance rather than efficiency.

Will the lip and spoiler add downforce?

They tidy airflow and add presence rather than transform the car. The front lip and canards reduce a little front-axle lift and sharpen the nose, while the swept rear spoiler adds a modest aero element above the boot. The i4 kit is styling-led, so treat the pieces as visual and airflow-tidying upgrades rather than a track-grade downforce package.

Should I have it professionally fitted?

Yes. Dry-carbon panels are more brittle and less forgiving than factory plastic, and the add-on skirts and rear spoiler need clean, properly prepared surfaces to bond securely. Correct panel gaps, secure mounting and clearcoat protection are a body-shop job, and professional fitment gives the flush, factory-grade result the kit is designed for.

Can I buy individual pieces instead of the whole kit?

Yes. The kit is built from discrete components — front lip, canards, side skirts, rear lip and spoiler — so you can stage the build. For a quick front-end change, start with the front lip and canards; for the full look, add the skirts, rear lip and spoiler over time. Contact AME Motorsport to confirm current availability of single pieces for your i4.

Build your i4 with AME Motorsport

If you are planning a carbon aero package for a BMW i4 Gran Coupe or i4 M50, AME Motorsport can supply the CMST dry-carbon pieces and help you fit the full set or stage the build. Start with the CMST body kit for BMW range to see the carbon components, then get in touch to confirm fitment and the look that suits your i4.