[tetsuo111]

I modified the front bumper trim with matching black metal grills for the large central radiator intake and two side intake ducts. The driver's side intake is modified to be a functional CAI inlet, leading to the airbox. The BMW cold air kit is installed to duct air to the front brake rotors. I plan to add silicone duct from the OEM parts to the rotor backing plates.

The same metal grill material was installed on the Performance Aero rocker panels, converting the OEM non-functional intakes into functional ducts. I plan to run silicone brake duct hose from the rocker panel intakes to the rear brake rotors before track season resumes.

The rear bumper is being modified by replacing the plastic vanity diffuser parts on the lower part of the bumper with matching metal grills to redirect and dump air flowing under the car into the rear low-pressure "bubble". This may reduce drag and increase rear downforce at speed.

The inspiration for the grills come from the BMW Z4 and M3 ALMS and DTM cars.

[tetsuo111]

Update: The mesh rear bumper screen project is deep sixed for the moment.

The fabrication and fitment will require heroic efforts because the screen needs a bottom support to span the width of the bumper without bending. I also planned to gut the rear underbelly of the car by converting the under panels and storage bins from 328i to 335i style because the 335i / M3 has a void behind the bumper to fit the mufflers. This would be much easier to install a stealthy rear diffuser. It seemed straight-forward when I first looked, but the parts count adds-up very quickly (a few under body trays, storage bins, heat shielding, new charcoal canister and mounting bracket, etc.).

Sadly, I'll install the OEM Performance bumper without the screen.

I'll revisit venting the rear at a later time.