Title describes the situation.
That cannot be intended, right?
If you go ahead and create a new project based on the advanced vehicle template, move the vehicle 100 meters in the air, and click play the vehicle will rotate while falling to the ground.
No response yet but I can give an update already:
So I was able to completely eliminate this personally undesired behaviour by changing the corresponding PhysicsAsset and replacing the asymmetric collider with a symmetric cube (scaled to fit the vehicle). I am quite content with that now.
Could I have done it another way though?
I still don’t understand why the shape of the collider influences the angular force mid-air.