[sjc]

I've copied and pasted this from the tech section about what happened today, please be aware while it's below freezing...

WARNING !
OK. Guys thanks for this thread, as I've had that exact problem today, and although I dealt with it easily enough, it would not have been good if someone else was driving, unaware of what was happening.
Started car, temp showing minus 3 degrees. After a couple of miles the temp went down to -5 and then quickly to -8, and we were on a Motorway and set Cruise to which may or may not have been something over 70 leptons.Nice quiet road, no dramas until a car pulled out in the distance so I touched the brakes and the Cruise lights duly went out. Still all fine, until I realised that the car has stayed at the speed and is now driving it self! No amount of pedal playing would free it, but using brakes would slow the car, but not seemingly the revs! As it was a Motorway, and felt I had a bit of control, I carried on until it became a duel carriageway and was able to pull over in a layby.Slowing to a halt, with my foot hard on the brakes, it was obvious that the car was still trying to pull forward,I put it in neutral( it's an Auto) and the revs were stuck at 4000rpm.With my foot hard still on teh brake, I put it in park,and turned teh ignition off. Restarted a couple of times and it was still stuck at 4000rpm, and no amount of blipping the throttle would do it. Flipped the bonnet, and played with the throttle manually, and after a couple of attempts it freed itself, ideld a bit lumpy for a few seconds and then fine.Continued the journey not going over 2500 revs and all fine, as was the same journey on the way back, again keeping the revs at sensible levels.
Looking at the number of occurences,there seems to be a link between anything colder than -5 degrees below and the throttle sticking?
Please all of you, be very careful, it's not a pleasant experience