Stumbled on this project, called Truggy, its an opensource design for a high end RC car. So if you are into the high end stuff, this might be another way to customize your car. Of course it doesn’t include motors, electronics, etc etc. However it could be a cheaper solution that buying (I see some RC’s go for $500 and up).
http://grabcad.com/library/openrc-1-10-3d-printable-rc-truggy