Just picked up my TDi 3.0 HSE yesterday :D with the proximity key. It only works when within about 1-2 metres of the vehicle and knows which door I'm at. Also (and I tried this since I have a metal brief case) the key won't activate anything if it's in a metal case, so that may be a way of isolating it safely inside the D4. In due course I'll try and see if a trailer hitch safe also prevents the key from "talking". Spare key is already safety-wired in SWMBO's purse so it may be the first-ever car I've owned in 30 years that she won't lose the key for it [bigwhistle] Maybe some day the access will rely on a fingerprint, so it's less likely to have stolen (unless a finger is removed:eek: )
