Bolts-SecretsThe idea is simple - a non-standard bolt shape under a special key. If it is difficult to unscrew, the cheater immediately switches to another machine.
There is such a set of rubles 300.
If any bolts will meet the attacker too often, he himself can buy such a kit with a screwdriver. This way of guarantee does not give.
Advantage and that you make it difficult for a traffic police officer to rent a room if he decides to do so.
AlarmThe thief approaches the car, the siren is working, he immediately leaves this site and will look elsewhere. This method is reliable and perhaps the best.
If you need to remove the numbers, you do not have to bother with rivets, drill them.