Approximate installation time: 1.5 hours.
Required tools: Drill, 6-8mm drill bit, 10mm wrenches + Allen key.
Installation difficulty: Easy (basic mechanical knowledge)
As you can see, the installation is quite simple, but it requires some patience and checking that everything fits properly to ensure it is all well-centered. Don't rush and make sure to follow the steps. Correct installation always guarantees a better finish.
Hardware (in parentheses for diffusers that include the differential add-on)
x4 - 10mm Spacers. (2 per bolt)
x2 - 10mm Spacers. (1 per bolt)
- Nuts - M6.
- Washers - M6 wide neck.
- Allen - M6x12mm.
- Allen - M6x16mm (bumper ends x4, optional)
x2 - Allen - M6x20mm (use with 10mm spacers)
x5 - Hexagonal - M6x35mm (use with 20mm spacers)
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The following image shows different marks to identify the position of the main plate and the use of the spacers. It is important to note that each bolt will have 2 washers, one towards the bolt head and one towards the nut, to achieve a larger clamping surface.
(NOTE: The image shown is the main panel of the V1 e36 model. The position of the bushings and the indicated bolts is the same for the e46 model)
Due to space constraints and to facilitate the work, it is recommended to first attach the main plate to the spare wheel well and mark the holes that would go to the lip/lower part of the rear bumper with the Hex. M6x20 bolts, attach the disassembled lip (if the bumper model allows it, otherwise, it is recommended to disassemble the bumper) and then return the assembly to the car.
Red square: 20mm Spacers + Hex. M6x35mm // 10mm Spacers + Hex. M6x25mm (Attachment to spare wheel well)
For the ends, it is recommended to drill 3mm pilot holes and use self-tapping screws to correctly position this part. Once aligned, use M6x16mm Allen screws here. (depending on the version, this part may have 2 or 4 holes per piece).
(NOTE: It is not necessary to use all 4 screws, but it is recommended so that the bumper adapts to the flat shape of the diffuser)
You will see that the central plate has holes with variable width at the ends. This will allow you to adjust the ends independently of your bumper model. It will also allow you to adjust the intermediate pieces to align with the exhaust tip both in inclination and in advancement).
