BMW 4 Series G22 G23 Carbon Fibre Competition Rear Diffuser Set by FORM (2020 on)

This product is designed for vehicles with quad tailpipes and we would recommend removing the rear bumper to install this product. Forge Automotive supplies this diffuser set and can fit it at our Darwen and Leeds sites.

Key features

• Competition rear diffuser, with or without rear winglets
• Carbon fibre (CFRP, 2x2 twill)
• For quad tailpipe cars

What's in the box

• 1 x carbon fibre Competition rear diffuser
• 2 x carbon fibre rear winglets (with the Include option)

Fitment

• BMW 4 Series (2020+, G22 G23)
• This product is designed for vehicles with quad tailpipes and we would recommend removing the rear bumper to install this product.

Good to know

• Choose with or without the rear winglets.
• Designed for cars with quad tailpipes. FORM recommend removing the rear bumper to fit it.

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 4 Series G22/G23/G26 parts.

Common questions

What is wet-lay carbon fibre (CFRP)?
Wet-lay carbon is made by laying dry carbon cloth into the mould and applying resin by hand, then curing at room temperature or low heat, sometimes over a fibreglass or composite base. It gives the same 2x2 weave look as pre-preg for less money. The trade-off is more resin and a little more weight, and the finish depends more on the maker, which is why we only stock wet-lay parts from brands whose quality we have seen.

Is wet-lay carbon strong enough for a splitter or diffuser?
Yes for road use. The part is still carbon reinforced and stiff enough for a splitter, skirt or diffuser. If you want the lightest, most rigid option, choose the pre-preg version where the range has one.

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.

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.