Source of upgrade parts:
http://www.happytimehobby.com/
Good motor:
http://www2.towerhobbies.com/cgi-bin...?&I=LXBPG4&P=0
Or:
http://www2.towerhobbies.com/cgi-bin...?&I=LXGFR6&P=0
Pipe:
http://www2.towerhobbies.com/cgi-bin...?&I=LXBPJ5&P=M
Aside from the clutch, my XR80 is nearly stock, no complaints. But I always wait to upgrade my car until after I'm very familiar with it. That way, I can actually see the diference expensive upgrades make...