At 1 o'clock this morning my horn started to blare. It was not the beeping of the panic alarm, but a steady blast. I started the Av hoping that this would stop it, but it kept going. I went to grab a coat and a wrench to yank a battery cable and lo and behold after about another minute it wound down and died. I drove it around for 5 minutes to make sure everything was operating OK, and then sat up for an hour t see if it would happen again. It didn't. I called the dealer and he said that this was not an uncommon problem and was due to the cold. It was -6 here last night, and his theory is that the cold caused the plastic/metal in the steering column to contract to such a degree that the horn was triggered. Short of taking it all apart, his suggestion was to pull the horn fuse when it looks like it's going to be below zero. I gues when I started the Av the wiring heated up enough to stop the horn. A friend had a Cadillac that had the same problem and he ended putting a toggle switch in to disable the horn. Has this happened to anyone else? Is this a GM problem? Any other ideas?