In absence of negligence, what pain and suffering can he even get above actual damages. If the claim's not worth much, a lawyer won't bother with it anyway, so the situation may provide its own answer. There is no such thing as an easy case. If there's a police report that says the driver was at fault (especially a conviction, finding of responsibility), the insurance company won't waste their time litigating the thing. Lawyer's are dang expensive, even though big companies with in-house counsel don't worry about the cost of legal action until they have to farm out trials, etc. to outside counsel. If there is no insurance to speak of, all is not lost. A small claims judgement wouldn't cost you much out of pocket (just time), and would probably allow you to put liens on any real property he owns (home, land), and even garnish wages if his employer will play along.
Adam
(this is not legal advice, just random ramblings)