I use a pressure washer set up with a foam gun to clean mine. First foam the honeycomb bits, as well as the rest of the car, wipe the painted parts with a microfiber mitt, then, using the pressure washer, set up so it has a fan spray, rinse the car off. To prevent waterspots, I use a master blaster to blow all the water off of the honecomb crevices. To keep these clean, I use Sonax polymer net shield to keep dirt from sticking. I've found this works great on the front and back plastic honeycomb parts.