I've done nothing to the body except clean it and wax it so far. I've only added my HD head unit, front speakers, and amp and sub to the interior. Under the hood I've changed the valve cover gaskets, put aluminum coolant elbows in, cone intake, ZZP 1.0 PCM, Plugs N' Wires (AL 104's) and a 3.4 Supercharger pulley. Underneath I had a catted downpipe installed when I had the resonator cut out and replaced with a straight pipe.