OK, don't really need a reply now, as the wife bumped the car this morning Not a huge amount of damage, but I suspect it may still end up being a write off. Anyway, because of that I swapped the aftermarket stereo out and replaced it with the OEM radio cassette unit and CD player unit, and the locking appears to be working again! Strange, as we fitted the radio about 6 months ago, and it's worked fine until now, so I'm just wondering if it's coincidence?