BMW M8 F92 CMST Carbon Fibre Kit Install Guide
This is an installation guide for the CMST carbon-fibre kit on the 2018-2022 BMW M8 (F91 convertible, F92 coupe and F93 Gran Coupe), covering the front lip and the carbon front fenders. The front lip is a tape-and-screw fit around the lower bumper, while the carbon fenders are a bigger job: they replace the factory wings, so the wheels, fender liners and the washer-fluid bottle have to come out, and the panel gap to the bonnet must be set by hand. Allow most of a day with two people and a hoist; the fenders are best done by an experienced fitter.
- Vehicle: BMW M8 F91 / F92 / F93, 2018-2022
- Pieces covered: Front lip (with corner extensions), carbon front fenders
- Fixings: 3M VHB tape, panel-bonding adhesive, self-tapping screws, factory fender bolts
- Difficulty: Front lip moderate; carbon fenders advanced (panel-gap setting)
- Time: Most of a day with two people
Tools and preparation
You will need a trim-removal kit, a socket set, a cordless drill, a trolley jack and axle stands or a hoist, degreaser, adhesion promoter, fine sandpaper, masking tape and a heat gun. The front lip relies on warm, clean, degreased paint for the 3M tape, so prep the bonding faces and only bond above roughly 15°C. The fender job is mechanical rather than adhesive-led, but it still demands careful panel alignment.
Dry-fit the front lip first to learn where it sits and where the screw points land. For the fenders, read ahead and stage the work: you are removing wheels and liners, so have the car safely supported and the washer-bottle area accessible before you start.
Difficulty and time estimate
The front lip is a moderate job. The carbon fenders are an advanced one because they are structural body panels, not bolt-on trims — getting the gap between the fender and the bonnet even on both sides is the part that separates a clean install from an obvious one. If you have not aligned body panels before, have the fenders fitted professionally. Budget most of a day overall, more if you are taking your time with the fender gaps.
Step 1: Front lip
Start by removing the lower trim strip from the factory front bumper, then offer up the CMST front lip and check the fit and the screw positions along the bumper. Bond the lip with 3M tape along the inner mating edge, peel one end of the backing, and with two people align it across the whole bumper before peeling the rest and pressing it home. Confirm the position, then pull back the tape end again only if you need to reset — once you are happy, press firmly and let it grab.
The M8 lip includes corner extensions and two small front blades (the centre "teeth"). For the corner pieces, first match each to its position with small locating holes, then bond with adhesive and fix the lower edge with short self-tapping screws so the corner sits tight to the bumper. The two centre blades are positioned next: confirm their left-right placement, bond with 3M tape and a few points of adhesive, align to the correct position and press firmly. Take care drilling near the front of the lip — it is easy to over-run a self-tapper, so use the right length and check behind the panel first.
Step 2: Carbon front fenders
The carbon fenders replace the steel factory wings, so the front corners of the car have to be partly stripped. Working one side at a time: remove the wheel, take off the wheel-arch liner and remove the factory side skirt section where it meets the fender. Open the bonnet. On the side that carries the washer-fluid bottle, the glass washer reservoir has to be disconnected and moved aside to clear the inner fender — drain or cap it so you do not spill fluid into the bay.
Remove the inner fender fasteners and take the factory fender off. Transfer the original fender's air-vent trim (the side gill) onto the CMST carbon fender so the car keeps that detail, then mount the carbon fender using the factory fender bolts. The critical step now is the panel gap: before you torque everything down, set the fender so the seam between the fender and the bonnet is even, and adjust the fender's position to match the gap on the opposite side. Step back and check both sides from the front of the car — symmetry here is what makes carbon fenders look factory rather than aftermarket.
With the gap set, reinstall the washer bottle, refit the wheel-arch liner and the side skirt section, and put the wheel back on. Repeat on the other side. Because this step involves alignment that affects how the whole front of the car reads, we strongly recommend an experienced fitter for the fenders.
Fitment tips and cautions
- Set the fender-to-bonnet gap by hand and match it left-to-right before final tightening — this is the make-or-break detail.
- Transfer the side gill trim from the factory fender so the car keeps its original vent detail.
- Manage the washer bottle. Cap or drain it before moving it aside to avoid spilling fluid in the engine bay.
- Mind the drill depth on the front-lip blades and corners — use the correct screw length and check behind the panel.
- Warm, clean surfaces for the lip's 3M tape; bond indoors in cold weather.
- Support the car safely on a hoist or proper stands while wheels and liners are off.
Frequently asked questions
Are the carbon fenders a direct bolt-on?
They mount on the factory fender bolts, but they are full replacement panels, so fitting them means removing the wheel, liner and washer bottle and then setting the panel gap to the bonnet by hand. It is more involved than a bolt-on trim piece.
Why does the washer bottle need to move?
On the M8 the glass washer reservoir sits behind the inner front fender on one side, so it has to be disconnected and moved aside to remove and refit the fender. Cap or drain it first to avoid spilling fluid.
What is the hardest part of this install?
Setting the gap between the carbon fender and the bonnet so it is even on both sides. That alignment defines how the front of the car looks, which is why we recommend an experienced fitter for the fenders.
Does this kit fit the coupe, convertible and Gran Coupe?
The front lip and fenders in this kit are designed for the 2018-2022 M8 across the F91, F92 and F93 body styles, which share the same front-end structure. Confirm your exact model when ordering.
Should I have it professionally fitted?
The front lip is within reach of a careful DIYer, but the carbon fenders really benefit from professional fitment. AME Motorsport can arrange installation in Australia so the fender gaps and the front lip are set correctly.
Get it fitted in Australia
For professional fitment, AME Motorsport can help. See the full M8 range in the CMST body kits for BMW, choose carbon wings from the CMST fenders collection, add a carbon nose from the CMST front lip range, and browse the wider CMST catalogue. Contact us to book fitment or for current M8 pricing.