[TodmordenLad]

Best £100 you can spend on car security, imo. Here's an excerpt from the AutoExpress review:

"For the ultimate in physical security, look no further than Disklok. Its design means it’s not vulnerable to steering wheel cuts, and it just spins when you try to apply force with tools. We also noticed areas where the product has been improved, eliminating weaknesses we had used when attacking the lock in past tests. And although other products hinted at approval by insurance research body Thatcham, Disklok recently had its status renewed. As a deterrent it is mighty effective, and it comes in a choice of colours if you think the silver of our sample is insufficient..."

We've got them on both our cars in an area where car theft isn't that uncommon. They're a good visible deterrent, they're very hard to remove without the key and the car can't be driven when they're installed.