Call me crazy, but when I spawn into a camp and get shot, I always hear the round hitting me. I don't hear the report from their barrel (unless it's close), but I always hear the thud. Even when it's not a camp, I always hear the thud. Is the thud sound directional, like the barrel report is? Can you tell what quadrant it's coming from via the thud as the round collides with the side of your vehicle?
I played around with FMOD last winter, and it is insane how accurate and complex the sound modeling is. Unfortunately it was so complicated that I never figured out how to add the old AH2 engine sounds. I changed a bunch of 20mm sounds and 50 cal sounds, but never got around to changing the vehicle sounds. Although that is totally and completely possible. That's on my hobby list, different sounds for the game. But right now I'm focused on berms and land objects. There's even an online course for FMOD developers that I was going to take but never got around to it because I got into map making. Berms first, land objects second, sounds after that. And I need to redo my kitchen somewhere in there.