Since LAVs are 1-hit-kills when they run over infantry, there needs to be some sort of balancing. LAVs should take some damage when they run over infantry. Not a lot; running over infantry should still remain a viable tactic, but LAVs should take enough to keep people from running over 5 players with the same LAV. I think the damage done to the LAV should be based on the mass of the dropsuit, so that hitting scouts do the least damage to the LAV and hitting heavies do the most damage to the LAV.
I also think it should be possible for a heavy to survive an LAV hit with a sliver health left considering that heavies are very well armored, and they are largely designed to handle vehicles.

If you are reading and you're one of those people who is all about "realism", consider that your car can get damaged if you hit a deer. Consider that people hit by cars can survive. Same can apply to scifi armored cars and scifi armored people.

I would prefer this over the current system of my LAV almost getting destroyed after tapping another vehicle.