I talked to the police today. They have a suspect, but he claims that the GPS belongs to his girlfriend. Luckily, I still have the box, which has the serial number. This will allow the cop to take it from evidence tomorrow (the evidence guy isn't around on Sundays, I guess) and turn it on and then check to make sure the addresses on it match those that I gave him. And then we'll "go from there," whatever that means. No clue if I'll have to be any more involved in it (give a statement or something), but at least I know I'll be getting my GPS back. Also, there's no small amount of satisfaction in knowing that this person was caught breaking into my car. I hope he was behind this rash of thefts and that they will now stop.