I always quite liked the James Bond solution to car thieves in one of the films. Car clearly had marked on it that car was fitted with anti-theft device. Anyone who tried to break in triggered car explosion. Only problem is that poor James had to replace his Maserati every time someone tried to steal it. But I am sure with a bit of fine tuning, this could be a real deterrent and could be adapted to bicycles. I also like the idea of having built in rocket devices in the front and back of the car to discourage tailgaters and people who cut in front of you. Rockets could be a bit heavy for a bicycle though.

Oh dear, I think I've been watching too much tv. Time to go for a ride - equipped with compact rocket launcher!