really hard control of the car, remove cluch, you don't need it. Make bigger fuel tank, and make that engine be more economic. I play 7 min but i still don't know how to drive, i start engine and when i press accelerator engine stops running.
When you connect two bodies with Strechted Hinge, right click on it, choose Script menu, then search for hingeConstant in that window you type 1e-030. Ant that is it. One more advice in Script menu find legacy mode ant type in there not 1 but 0.Then your circle can spin very fast. Good lock!
Wheel, i know much about engines... The pistons have to be rectangle, cylinder must be bigger. More kg/m^3 if you want more power. Try lot of times and choose best speed. Good luck.