hide a switch for your fuel pump + have an alarm..
i feel ya, iv had my car broken into twice, both times they stole $800+ in stereo equipment and i never got it back. my friend just recently had his celica gt stolen, and he has given up hope. if theres one thing iv learned, its that stealing is okay.. the theifs get off with a ton of money and car parts, and the victims just get fucked into paying for a new car that they dont have the money for.