Utter scum. knighty is right through, your insurers should cover and sort it, after all it's not your fault he was uninsured! If I were vindictive I would also make it my business to seek retribution, but wait around 6 months so there is no chance of you being suspect. Wait for his car to return and accidentally put a few dents in it one night, maybe take out all 4 tyres...
If I were vidictive