Hi martman:
Firstly, all three of you should put the matter in the hands of your respective insurance companies who can jointly pursue whatever enquiries need to be made etc.
Notwithstanding the fact that a stolen vehicle was involved/responsible, your insurance companies can seek recompense via an organisation called the Motorists' Insurance Bureau (MIB).
Sorry to sound negative now but regarding the culprit, in my experience these idiots have no money, hence the reason why I've suggested the MIB.
It doesn't mean, however, that you can't try to sue the culprit but might be a bit like trying to get blood out of a stone.
Good luck.