Neutral.It's good because it can be the reason to add "Fire-Fighter/Fireman".It's NOT a good idea because it will cause some road-blocks and people while they are driving , they hit the blow-up cars.
How about airstrikes? If the car dosen't blow up then we cant kill arrest by shooting a car, then we need to jump out and start hunting. Once he is arrested we will need a new vehicle to bring the arrested guy to the jail.
The fire that is on the car could also lower the players HP if he doesn't get out.