I think vehicles should tear like irl, I mean you can rip almost everything in real life so it would be cool if it was in the game.
Too hard to simulate. Its impossible, because when beams break, the collision triangles within them break too, so you would have a big hole in the car with no collisions. It would also require infinite break groups, which would also be taxing on your computer. The devs have already thought of this, but it simply isn't possible to do while maintaining a playable game.
