I recently started to notice that my 2005 s40 T5 starts to rock back and forth gradually as my engine heats up. It mainly does it when the engine temp Is at its normal operating temperature; it rocks to the point to where the whole car is moving and I can see my rear view mirror and the things I hang on it shake. It's been about a week and a half that it's been going on. Any clue as to what it could be? I've regapped the spark plugs and that about all I've tried. Thinking of checking my MAF and throttle body and cleaning them up while I'm at it. I hope someone can help me out with this, it's really making me worry. Thanks.