[ODE] Car Physics with a couple errors

[mlist1 at binaryfortress.com]

I have created a car using a box for the chassis, 4 spheres for the wheels
and 4 hinge2 joints to connect the wheel to the chassis.  Axis 1 is for
steering and axis 2 is for rotation.  I have set the hi/lo stop of axis 1
for the back wheels to 0.0, and I've messed around with the CFM parameters
but I just can't keep the back wheels from turning.  If I'm driving in a
straight line then I turn the front wheels and start driving in a circle,
the back wheels start to turn as well, and I end up just spinning in a
circle.  Is there anything I am missing?  I have tried using the AddTorque
function to rotate the wheel, and I've tried using the Vel2 and Max2
params to rotate it, but nothing seems to fix it.

Any thoughts would be much appreciated.
Thanks