Let me get this straight.
He hit you on purpose a few times. (That is an intentional act, and would not be coverned under most insurance.)
He stopped, got out and wacked your car with a bat when you drove down a dead end.
He chased you to a PD station, and you thought he might have had a gun.
Ok, here is what I'd reccomend.
1) His insurance will tell you no coverage. (He's got to confirm that this even happened, and he will not likely do that.)
2) He is a dangerous fucker for sure. Do not screw with this guy unless your ready to put him in the ground.
3) If you can get some cash, take it.
4) If it was me, I'd think of something that would put this ass munch away for life, like murder his punk ass girlfriend and set him up for the murder.
Screw that, just knock them both off, and you could get to act out your frustrations on her like you want to do as well. (and if you do it after you get the cash, you get to walk away with some change too.) LOL
Seriously, either walk away for ever on this one, or be prepared to take it all the way to the grave for one, or both of them. (IF you leave her around, she iw going to tell you off to the PD, and your going to need a good alibi to keep yourself out of jail.)
Things like burning his car down are just going to piss this guy off. (And if he's pissed, you want to know exactly where he's at, all the time.)
SO, do nothing, or do something, but figure if you try anything short of either walking away or planting this asshole, any middle options are not really going to get you anything desireable.