According to Auto Evolution, the kit reportedly adds 4 inches in the front to fit 10.5-inch-wide wheels and a massive 7-inches more in the rear to snug in 13.5-inch-wide wheels, but spinning around the BMW in these images makes the changes look even more extreme. Beyond just the extra room in the fenders, the lower air intakes are ready to suck in huge volumes of cool air, and there's a front splitter to keep things planted. The front and rear extensions are joined by side sills that grow the farther back they go. Finally, at the rear, the M4 gets a reworked diffuser with mesh inserts.
This is just the type of automotive craziness that makes SEMA interesting. Take a lot at it for yourself in the gallery.