After loosing 3 car stereos to A$$hols like that I superglued some Razorblade pieces to the nuts under the dash. A week later I came back to a car that was full of blood but the stereo was still there.
That was the last time that car was broken into because the Cops found the punk.
He tried to sue for medical cost, after receiving more than 50 stitches on both hands and fingers. He told everything that had happened to the Cops. I received a phone call that I had to be at home the next day at 4:30PM so they could look at my car... and "He" the cop "did not think I had any razor blade under the dash". That was a good enough hint for me to remove the razor blade pieces. Next day the Cops did not find anything under the dash, they charged him with over 30 counts of theft and vandalism from different cars.