I for one see alot of burning tanks driving around the map. Many of them don't even care about it.
Quite the issue that a near disabled tank can still operate as if nothing happened.
PR has a mechanic that causes the turret to lock when when enough damage is dealt to a vehicle. Unlike the movement thing which is buggy, this one works just fine and forces people to stop combat after taking a hard hit. Could be a good idea, still allowing you to drive the tank to safety for repairs while preventing you to fight (the turret is really stuck in the position it was at when the damage occurred, making any kind of aiming impossible).
Could be implemented for when a vehicle's HP is below, say, 60%. As for burning, it really should deplete HP even if the vehicle is crewed.