When you blow up inside a vehicle/aircraft, the explosion sounds are very quiet, as if they were happening far away.
I find this game breaking, because if you are inside a tank and, say, a helicopter hits you multiple times with rockets, it's impossible to clearly determine that there are rockets directly impacting the tank.
This often with a sudden explosion, that you also can't clearly hear, even though you are inside the explosion!
All of this forces me to switch to 3rd person to see what's going on, which is cheap.
So, what I'm suggesting is, the explosions from things that hit directly a vehicle you're inside of should sound loud and clear.
And maybe the explosions could also sound more muffled and/or have more bass in it, to make it clearer that the BOOM is happening outside the vehicle.(Should not apply as much to open vehicles, like the door-less version of the Offroad, the Hummingbird, etc.)