Now the first time this happened to be i thought it was a floke, but its happened afew times since then, what is it thats been happening to the APC?
Well it turns into a wreck for no apparent reason, no explosion, other than hiting say, a tree or bump at an odd angle, is there a problem with apc collision bahaviour? or am i just a really bad driver?
It would help us if you took a screenshot of where it happened, or record a video for us. It could be a mapping problem, or like you said, a collision problem. (remember that the apcs are still vanilla, and this could be a vanilla problem.)
This happens with all vehicles. On a static object, there are points I call killzones. Sometimes, it's the point of a rock, sometimes, two statics are necessary for creating the kill zone, but I have experienced this. I drove a Humvee onto the tip of a small rock, and managed to get the rear wheels off the ground, with the rock supporting the middle. The Humvee then started to bounce around with the rock as the fulcrum, and then spontaneously wrecked.
I also tried to get a tank into a narrow alleyway, between a trash can and another wall, and when I finally got it through, it turned into a wreck immediately after.