Stabilising mesh / align on z axis

Please, if you got linear / angular damping in mind then think of soemthing else.
I have been searching for a thing like this on the forums and i found lots of threads with the same topic
but there are no answers almost.

So ,
Im trying to make a decent vehicle controller, (hover car ), but when I run over fast terrain, even with angular damping,
the hover turns sometimes into the ground or air and then makes some very weird stuff like flying into space.
Sometimes it just falls onto its back, too.

So how do I make a realistic and futuristic looking blueprint that aligns (but not locks ) any mesh on the z axis?