Don't go the realism route m8. It's a video game, keep it to "it isn't fun" or "it is unbalanced". A lot of things in this game aren't realistic. If it were real close to real life, it would be a simulation, not a game.
I think this suggestion makes sense since in the past, when this HP fit, vehicles could be spawned in over and over. Now that it's only once a war, the vehicles should have more health to sustain more damage. Also, there is a feature or bug of the vehicle mod that applies all damage the vehicle takes to the driver as well, even if the driver is not shot (for example, if the rear of the vehicle was shot with the driver way out of the line of fire). This makes vehicles extremely easy to take out with one sniper shot killing the driver, and heavily damaging the vehicle.
I think we should be specific with what you want done, like how much HP should it have, or how many bullets should it be able to take so Garnet can do less guess work if this was accepted. I would think that quadrupling the HP of the vehicles and getting rid of the ability for any damage the vehicle takes to apply to the driver as well would suffice. I don't play MRP anymore though, so you guys would have to test this out, see if that's what you want.
+1