Even if the crooks had a RF generator with your freq, they still can't start the car up without the specially cut key. And if they try to tow it, it will look suspicious hauling the car around to your hideout with the alarm blowing full blast behind a tow truck. Granted you can't just pop the hood and disconnect the battery, which would make it possible. So I guess installing a small 12 volt battery hidden away in the trunk would be a good idea for back up.