i think the best solution would be to make it hard for them to get to your car.. as people have mentioned: sensors, different lock nuts etc. this will probably stop them from coming back.
but i also think that some people need to be taught a lesson.. a lesson making sure they don't go and steal people's cars/parts again! i would get mates down, get them into the garage, cut their figertips off, then burn the tips to stop blood loss put their thieving hands to a stop!