I have installed a fuel filter like this on my car, in the trunk :
http://aeromotiveinc.com/products-pa...e-fuel-filter/
It has a shut off valve built in. So even if a thief finds my fuel pump switch and starts the car, he will only get a few hundred yards before the fuel in the carb runs out.
Not foolproof, especially if the thief brings a tow truck, but it will slow down the joy riders.
Plus you will get notified of the theft a lot quicker when someones calls the police concerning an abandoned car in the middle of the road.
cheezer