BMW 3 Series G20 G21 LCI Pre-Preg Carbon Fibre Rear Diffuser Set by FORM (2022 on)

The FORM Industries Performance Rear Diffuser for the BMW 3 Series M Sport LCI has been made to provide a bold centre piece on the rear of the vehicle. Forge Automotive can supply this diffuser set on its own, or fit it at our Darwen or Leeds site.

It is constructed from 3 pieces of pre-preg Carbon Fibre.

Note: This kit is for European cars only.

Key features

• Three-piece rear diffuser: centre and two sides
• Pre-preg carbon fibre, 2x2 weave
• Uses the factory clip points and screws
• For European specification cars

What's in the box

• 3 x pre-preg carbon fibre rear diffuser pieces (left, centre and right)

Fitment

• BMW 3 Series LCI (2022+, G20 G21)

Good to know

• FORM state this kit is for European cars only.
• FORM suggest applying any ceramic coating or PPF before fitting.

Supplied, fitted and finished by Forge Automotive

Forge Automotive can fit this diffuser set at either of our sites: Darwen in the North West or Gildersome, Leeds in Yorkshire. Forge Automotive can also finish this diffuser set before fitting: paint protection film (PPF) to guard the carbon, a colour change or satin wrap, or colour matching to the car. Ask when ordering. See more BMW 3 Series G20/G21 parts.

Common questions

What is pre-preg carbon fibre?
Pre-preg is carbon cloth that arrives from the mill already impregnated with a measured amount of resin. The part is laid up in the mould and cured under heat and pressure, usually in an autoclave or oven. Because the resin content is controlled, the finished part is lighter, stiffer and more consistent than a hand-laid one, with a cleaner weave and better dimensional accuracy. It costs more to make, which is why pre-preg parts sit at the top of a range.

What does "dry carbon" mean?
Dry carbon is the everyday name for a pre-preg part: carbon fibre all the way through, rather than a carbon skin over a fibreglass or plastic base. The surface still has a clear lacquer, but there is no excess resin in the laminate, so the part is light and rigid.

What is a 2x2 twill weave?
The weave pattern in the carbon cloth. In a 2x2 twill each strand passes over two and under two, which gives the diagonal pattern BMW use on their own M Performance and M carbon parts. Choosing 2x2 means aftermarket and factory carbon on the same car match.

How do I look after a carbon fibre part?
Treat the lacquer like paint: wash with pH-neutral shampoo, avoid harsh solvents, and wax or seal it. UV is what ages carbon, so a protected finish lasts longer. Forge Automotive can apply paint protection film to any carbon part before fitting, which guards against stone chips and keeps the weave clear.

Can I fit it myself?
FORM rate it moderate, 30 to 45 minutes with trim tools, a T20 Torx driver and an 8mm socket: unscrew and unclip the original diffuser, test fit the three pieces, clip in the sides then the centre, refit the screws and recheck after a short drive. Forge Automotive can fit it at either site.

Fitting is available on every part at our North West (Darwen) and Yorkshire (Leeds) workshops. Prefer to fit it yourself? Fitting instructions ship with every part.

In-stock parts ship in 3–5 working days, fully insured. Every part is fitment-checked before dispatch.

Covered by the manufacturer warranty. Fitting through our workshop keeps it intact.