Fix the collision system
No one seemed to have noticed the box-physics are all square poly based physics UNLESS you use an in-game part rather than create your own, that require better collisions of mesh than cornered ones. i.e. circle collisions, etc.
I mean, I get it..."simple" planes, but that is geometry disaster in a fundamental way. You cannot drive on a cylinder fuselage wheel for example. It is seen as a box and your vehicle will jump for no reason. Thats just one example. You know how things randomly explode? yeah....thats prob why. They are colliding, you just dont see it. Might force request 3 refunds if not fixed :/ I love this game, but this was a deal breaker tonight :(
I'd get access to XML if I were you.