The Yellow 2004 Acura NSX is one of the first generation Xmods that came out as a starter kit. You were able to buy additional upgrade kits to fully customize your Xmods.
XMODS can be extensively modified using parts supplied by RadioShack and other aftermarket vendors. The starter kits advertise the ability to change the motor, wheels, tires, trim kit, springs/shocks, and bearings (From nylon bushings to steel bearings), add lighting kits, and swap the crystal to allow the cars to operate on multiple frequncies.
Even though each model has a different body, all models in a particular line share the same or similar chassis. The most notable difference in the chassis is its length relative to its body top.