Ha much better , some comments.
are you controlling the steering with an analog control?
when I see from the first person, it looks like you have a keyboard which is an all of nothing controller. That makes it very hard to control the vehicle when driving straight.
In the demos I can not do analog control because the GUI does no support it and the demos are very basic, but try doing analog steering first and fort most.
If you are then try to apply a gain factor to the steering, by this I mean
pretend that the steering wheel is a big wheel, the bigger the wheel the better the control.
There is a show called MythBusters. when they demonstrated the effect of controlling a vehicle with a standard remote control with a small steering button and the vehicle always tumble from side to side just like your video. Then they switched to using a very big steering disk and they can control the vehicle very smoothly. After that now they always use the large bus steering wheel to control vehicles.
The way you implement that is that you can add a gain ratio between the input from the controlling device and the value you pass to the controller. Say you say that gain 0.5, now for each turn of the steering only half turn goes to the controller.
The OFF and all the serialization can be used is jut that I has not implemented then for the dNewton
but you do not when to serialize using OFF, because OFF is a standard format that can not contain the internal connectivity that newton use internally. The reason I use OFF and not OBG, is that OFF support arbitrary polygon so for fix bugs is better than OBG.
what do you want to serialize I assume the streets and all the background.
I can add serialization to the dCollision this weekend.
you can modify anything, I never try updating the wheel but it is possible yes.