Works on any car except some cars like Ferrari where you cant customize individual body parts. Just apply the extreme parts (marked by orange) for all components. the last part is unlocked at rep level 50! so it cant be unlocked any earlier. Then go to handle tuning and move the sliders for each category individually all the way to the right(grip) or left(drift). You will probably be just an inch closer to achieving your target. That inch is obtained by applying other spoilers over the stock spoilers. Go to visual customization to apply new spoiler. This will unlock the downforce component which was previously locked in handle tuning section. Slide this as well to right or left and confirm the settings and the achievement will unlock