Just another heads up...
http://www.access.gpo.gov/nara/cfr/w...cfr571_03.html
If you modify this vehicle, you may be breaking the law if you don't adhere to the government's safety standards. I'm guessing at some point you are going to have to drive the thing on the street. These laws are here for a reason, stay safe!
Also, there are laws governing radio control. You may want to check with the FCC.
Not that I'm a lawyer or anything
Good luck...