When coming to a stop at a stoplight -- If the light changes before I manage to make a complete stop and I accelerate, sometimes the transmission seems to slip a bit and then 'catches up' with the engine about a half-second later, causing a fairly loud clunk and of course it can be felt by the driver / passengers. This can also happen sometimes after a complete stop, but it is so intermittent that it's hard to tell. The problem hasn't gotten any worse in the time I've owned the car, but obviously it shouldn't be happening at all. I noticed the exact same issue in my 2004 Aztek as well. Both are the AWD models, if that helps anyone.