thanks for the thoughts,
actually, i don't think anyone in their right mind would steal my car right now, it's a W123 200T ! trouble is, these days not everyone is in their right mind. the 200T is a barge, but i love it.
i am not so worried about it now as i haven't started work on it, but i fully intend to gently restore it to it's former glory and keep it as the ultimate low-cost classic utility vehicle.
my friend keeps his aston vantage unlocked for the same reason you mentioned, frustrated vandalism, but where i live, once the joyride is over it's bonfire time. so i'll take a smashed dash everytime. i'll check out your wiring suggestions and go for one of them.
in the meantime i've put in a 12v flashing diode so it looks like it's got an alarm. apparently most alarm/immobilsers are so good nowadays that thieves spend most of their time trying to steal your keys first. sometimes even putting fishing rods through letter boxes to hook them out of your hall.
long term, i guess i'll have to put an alarm in
thanks once again.