@ventilator:
I am using a P4, 1.9GHz with MSVC.

One thing I did notice today with terrain is that not all four wheels make contact with terrain, e.g. in Frame 1 there would be 3 wheels on the floor and in Frame 2 the remaining wheel would be in contact, whereas on level geometry all 4 wheels return contacts. That bug will probably be solved by tomorrow.

A few things I noticed about your original car demo is that the vehicle tends to flip easily. This can be greatly reduced by making the car chassis very light and the wheels heavier thus lowering the center of gravity. It's also worthwhile to adjust wheel friction to current speed. Finally for future A6 versions that have auto-disabling (and a 30% framerate increase, yippee!) unnecessary calls to phcon_setparams/setmotor should be avoided, i.e. don't change the motor speed if it's already running at its minimum.

The crane AVI showed one sphere getting stuck in the crane. Fixing penetration detection is #3 on my physics list right now.