I recently had a break into my ford cortina and the radio stolen, so I finally got round to installing an anti theft device. I had a quick look on the internet for the options but ended up down in my local halford. They insisted I purchase a dislock and car alarm system. The disklok is essentially a great piece of kit, it stops anyone driving off with your pride and joy. It fits easily over your steering wheel and has a special unique key which only you have, the downside with this being that if you loose the key you have to fork out a further £20 to get a new one! However the whole system is fairly good value at around £40. The only major disadvantage is the weight, being extremely heavy and quite difficult to handle, especially if you're elderly.