The RS4 has new design of the center wing tower, it increases the rear stability without losing top speed. The RS4 body comes 3 different thicknesses body shell. The lightest is 0.4mm, is recommended for use at a high traction track and can change traction roll characteristics. The 0.5mm body works at all conditions because the body shell is harder so it can transfer more downforce to the chassis and increase overall traction. The 0.7mm body shell is heavy and strong, and it is recommended for drivers who want a very stable and long-lasting body shell.