A couple of days ago my car started shaking. It's not that annoying vibration when a wheel needs balancing; I mean the car was shaking, like if I grabbed you by the shoulders and shook you back and forth an inch or so at a time. Ten minutes later, after checking the car and finding nothing visibly wrong, it was fine. My mechanic had a brief look but could see nothing. He assumed something had stuck to the wheel and had been shaken off again. Today we spent a rather filling afternoon at my in-laws, who live about 30 miles away from us, straight down the A1. On the way home, at 70 mph, the car started shaking again. It's actually more bearable at high speed but I wasn't silly and pulled straight over. Something smelt hot; it was that smell of trains, so possibly a brake pad. My car's an auto but if it was a manual, I'd say it smelt like a burning clutch too. If it was a sticky caliper, I would expect the smell. What bothers me, though, is that the car didn't pull to one side, it just shook like crazy. On reflection, I would say that the shaking was being transmitted directly through the steering column - the steering wheel was actually moving left and right, like an unbalanced wheel on steroids. I have had no warning lights come on. Something else that may or may not be related: when I put my foot all the way down, the car kicks down but then has trouble changing back up. If I don't keep my foot on the kickdown button, it will change gear normally. I can accelerate just fine, but not if I use kickdown. This has kind of screwed Christmas. :( Any ideas guys?