my jeep for pb4a seemed to have some nice physics, a little drifty but was quite good... was quite a small model. the physics actually came from a pb3 model, and seeing as the physics code had more changes, things all acted as though they were driving on ice...
get one of the Dev team to fit some goodyear's and it might be okay... here is the physics data. its not brilliant but is a start, sorry i dont really have that much time to play with it either...
[TrackedVehicleClass]
omegaSpin = 0.6
velocForward = 20.0
velocReverse = 10.0
accelThrust = 30.0
rollSteer = 0.01
pitchThrust = 0.002
pitchPitch = 0.001
[AssaultTankClass]
yawRate = 4.5
pitchMin = -0.1
pitchMax = 0.8
EDIT1: oh i forgot... ask Nk1 for some physics info from Arc-mod if hes done any, i know they had a lot of civilian-based stuff in there...
EDIT2: further forgetations, ZEmod has some good cars in it!