In RC cars its the chassis that really defines the car. Two 1:1 vehicles can share a frame/driveline/suspension and be completely different vehicles because of whats built onto it. For us all thats built onto the frame/driveline/suspension are body mounts and a body, and we change bodies often and the only real different is aesthetics. Think of the Rustler and Stampede, pretty much every part is common besides the chassis and they are totally different rigs, even when using the same wheels and body.

Bottom line is, to have different cars you need different chassis.