thing is even a basic Cat 2 immobilisor has 2 circuit immobilisation so youd need to know exactly where to hot wire to get round it and youd be relying on the immobilisor cutting into the circuit in the same place on all cars (something a decent fitter should be doing is not putting everything in same place on cars!!).

even so its not a few seconds job.

5 seconds to get in car, 1 sec pop bonnet so accomplace can rip off and smash alarm sounder/car horn, 5 secs to get off steering lock/snap column lock, 5 seconds to get off cowling to play with wiring, 5 seconds to pull off ignition switch insert screwdriver and start car and get moving. so thats 21 seconds.

Youd expect an immobilisor and modified disklock to add minutes to that time.

Concerning if theres now major weakness' in common immobilisors!!