Thanks for the replies, the Autowatch does have overide process in case you lose the key, but when I made a brief call to the guys that installed it he said the overide process (Another company posted the proccess here
http://www.abacuscaralarms.co.uk/man..._prog_keys.pdf ) doing the overide would only disable the unit in the same was as the key.
Car wise no unusual locations just in the road at the girlfriends.
What did seem odd about the factory immobiliser was even without the key in the igntion, I can't recall seeing the key symbol on the dash flashing it's LED to indicate it was armed.