Cars are tipping over and twisting. Sketch of solution. Edited.

[ghost]

Problem
Cars are tipping over and twisting.
Reason
The center of mass of vehicles is located in center of shape, (the biggest problem) at half the height of the car.
Solutions
The attribute of center of mass in bullet is stored in btTransform.

1. We can manipulate it with function setOrigin(), but it has influence on physics. 👎
2. Better Wrapping vehicle's shape in btCompoundShape. Easier and it also allows to characterize cars with one more attribute. Useful in future. 👍
   Useful code
   https://www.gamedev.net/forums/topic/641015-setting-up-a-vehicle/
   Just in case:
   https://web.archive.org/web/20170903192733/https://www.gamedev.net/forums/topic/641015-setting-up-a-vehicle/

[ghost]

Unfortunately it isn't the guilty. :( it looks like something connected with suspension.

[ghost]

Succeed by #416.