Apparently this is a thing. A quick Google tells me this has been happening across Kent (and Sweden and Belgium it seems!). Anyway my car window was smashed and the steering wheel missing when I got up this morning (Elmwood Road, North Dulwich)rendering car immobile. I think I'll be buying a disk lock or something similar once I get the car back from the repair shop. http://www.halfords.com/motoring/car-accessories/car-security/disklok-steering-lock-silver-large Beware.