btRayCastVehicle positionalfriction

[e3dALiVE]

bullet vehicle kit had variable: maxVelocityForPositionalFriction(default:0.1f)
To avoid sliding at slow speeds or when the handbrake is turned on, we
introduced a positional friction model (since Havok 2.2.1) into the vehicle
friction solver. This extra friction is particular useful for slow driving
cars. To avoid letting this friction influence fast cars, you can set
maxVelocityForPositionalFriction to the maximum velocity, up to which you want
this extra algorithm to be activated. Defines up to which speed the positional
friction model will be used.
Does bullet raycastvehicle have something similar?
because without it my car is slowly sliding off the mountain even with i apply infinite force to the brakes.
Does bullet vehicle have linearcast(convexcast) or should i implement it myself based on vehicle raycast?
video: http://www.youtube.com/watch?v=Q6u6o-fpq-E

[Skuzz]

btConstactConstraint.cpp, function resolveSingleBilateral()

btScalar contactDamping = btScalar(.2f);

Adjusting this var to 0.7 has some effect.

[e3dALiVE]

thank you