This guy is obviously a nutter so i would be hesitant in taking a civil action for injury, just in case you P$$$ HIM OFF AGAIN.
You have to remember one thing "is the offender a mark for damages" ie can he pay you money if an award is made , Going to court for compensation is not as easy as you think , and getting an award of money and actually receing this money are two different things.
I suggest giving the Guards the estimate for the car (which they will need anyway) and let the judge make a ruling for the criminal damage, thats their business. If compensation is offered and it is near to your repair figure just take it and get on with your life.The offender will only offer Compensation to you in order to ease his conviction.