cheapest alam system i can think of off hand would be to just take the master fuse out. let'em get in it and try to drive off, i don't think they'd make it very far with no juice..

hope you catch them bastards.. i k now personally, theres a cop lives in teh trailer park next to my house, so if someoe tried to jack anything of mine, he'd get a few .22 bullets in his trunk then i'd let the cop chase after him, lol...