First build the little VMG axles were too weak:
Second build worked great but, I wanted more off-road traction.
http://www.youtube.com/watch?v=kn_ALo_UnPw
I wanted to add a driven axle to the front so I made a dual output shaft box for the back of my Tamiya trans which I posted on another thread:
I have the front axle & trans finished, I'll post up more pics soon.