The best kind allow the engine to run for fifteen to twenty seconds then shut down. The crooks think this is due to a mechanics fault and not a security system.
With diesels that absolutely must have glow plugs to start summer or winter, disabling the glow plug circuit is wise. A rare few would ever think a diesel no start was security related.
I had a friend with a brand new Ford E-350 diesel welding truck. Parked it downtown San Francisco. Came back four hours later, driver window smashed nothing else. He had pasted a sign to the steering wheel TOW TRUCK DRIVER DO NOT START FIRE DANGER