Hi,
I ve got the best results by using a 1:30 gearbox from
www.mikroantriebe.de that is mounted by springs. The frontaxle is also mounted by springs.
So every axle can move on its own an the body of the car is still upright.
Some cars that using axles without springs (or very soft springs)are instable.
That why I use a strong kind of brass plates (In german = "Federbronce") as springs. Normaly this one is using at the modelrailroad as electric connection to the wheels.
Here you should see a picture of a driveline using the named gearbox (the springs are here not to see)
best regards
Thorsten
www.mikromodell.de