The current generation of M3's have proven to be solid track cars right off the production line (and after the break in service). They've given the G8X much better brakes to match the size and weight of the car, but there are modifications that aren't changing the brake pads that can improve the overall braking experience. On this particular G80 M3, we opened up the fender liner portion where the airflow comes in to the wheel well, replaced the factory backing plates with carbon fiber plates that have airflow cutouts for better cooling, and replaced the factory radius arm/thrust arm bushings with Powerflex polyurethane bushings.
The front thrust arms (AKA radius arms/upper control arms) handle most of the frontward g-force under hard braking, and as such the bushings do tend to wear faster. Changing to Powerflex polyurethane bushings in these control arms helps stiffen up the front end under hard braking and turning and they tend to last longer than BMW factory bushings. While the designs of the F8x and G8x front arms are virtually the same, Powerflex says they are not interchangeable.
Opening up the fender liner duct and installing the carbon fiber backing plate (with brake duct design) cools the brakes so it mitigates brake pad glazing and brake fluid from boiling.
