Maldorf:
Sorry for your families troubles. It certainly can be hard to get your head around when they arrive in this fashion.
As far as a few issues you raised:
1) My insurance (forced by law) gives an allowance for the diminished value of a car. I found this out because they mailed me a $1300 check out of the blue for an accident from years before with a letter. You may want to check into that. It certainly will detract from resale value for the first few years. After 100k plus miles or seven or more years, not so much.
2) Your insurance company has a right to sue him, her, etc. You probably only will get your $500 plus court costs, as your insurance is paying. For kicks you may choose to file in small claims court anyway and get the judgement. Even though you may (probably) will never receive your money, if filed with the county, it will usually show up on his credit report as a "Public Record". If you have no other public record the hit on your credit is horrendous. It will last for at least seven years and can be renewed. You need to check laws in your state. Usually you have to document some effort to collect in order to renew, but you could conceivably wreck his credit for twenty years. Not much but something. If he does show up in small claims court you may have the right to question where he works which will give you a place to serve a "garnishment" of his wages. A copy of the arrest report mailed to an employer can have negative results as well.
3) Complaining actively to the solicitor/prosecutor and making MADD in this situation aware will step up the heat/punishment a notch. Unfortunately him having these arrests close to each other will help a claim of a "short term" problem instead of the chronic problem it may be.
Again, I'm sorry for the violation your family has endured, let me know if I can help, my cell number is the same.
Pekkerwood