First of all, Joy Riding is theft. Wcollera, you said you had "fire and theft" and therefore if your car was stolen and damaged in the process, your theft insurance should cover that. If they try to weasel out of it, just show the case law part that lists joy riding as theft and that should be that.
Second, let your insurance deal with it. Your insurance can pay you, and his insurance can pay your insurance. It may be different in OH, but here in MA, if you drove my car and wrecked it, MY insurance would be the ones covering it - even if you had full insurance. That is because it is the CAR that gets insured, NOT the driver!
Now, I don't mean this to sound bad, but there are a bunch of pristine, low mileage GTS's for sale. Now is the BEST time ever to buy! I would make sure they give you the FAIR value of the car - enough to buy a BETTER one and hopefully have some $$ left over.
As for your friend... I don't know how the two of you are and how far you go back, but it sounds like he is in a world of hurt (physically, emotionally, and financially). I would not try to make it worse - he has a banged up kid, a business suing him (his insurance likely WON'T cover that) and lost a friend. This is going to impact him for YEARS to come. While he may deserve every bit of it, I bet he is the last person who figured this would be the outcome of his actions. Remember... the next time you are going 150mph on the highway, the only thing that seperates being cool from being the biggest idiot ever, is whether you prang the car or not.
This guy rolled the dice and lost... and he lost bad. But I tend to think it's a decision others have made - or (god forbid) even worse decisions. Stupid father for drinking and driving with his kid. This will stay with him for a looooong time.