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.

I really really hate that. Bump into a friendly HAV, and massive explosion

While joyriders are immensely annoying, getting rid of them is easy enough if you have a decent team. A couple of militia swarms will take care of the problem.

I agree, we are wearing suits of power armor

the rest of this post is irrelevant for purposes of response

Well I don't care for "realism" justification for stuff like this, but if you insist on going that route it'd be relatively easy to imagine any of the suits surviving impact with a LAV. Aside from the shields, aside from the advanced armor, the clones themelves are genetically engineered and cybernetically augmented. They're super-soldiers. They don't quite behave that way in gameplay terms, but in the fiction, I mean, it isn't like they're cloning average jackoffs and using them to house the consciousness of the mercenary characters Dust players represent. It's perfectly reasonable for supersoldiers encased in advanced defensive technology to be a bit hurt but generally fine after being hit by a vehicle.

That said, the important part is that it's crappy gameplay, and the result is people driving around in LAVs with no gunners attempting to get free kills by holding down the forward key. Probably not what one might imagine when envisioning what a Light Assault Vehicle would be used for in Dust.