I just bought my 2010 2.5 s sedan with 57k miles. after driving for a day or two I noticed a light shaking when I accelerate between about 10-40mph. its not violent at all but I definitely feel something. however it stops when i get above about 40mph. shakes at idle occasionally but not consistently, and even just lightly accelerating. and when its doing this I noticed my mpg gauge goes up and down too then stabilizes when the shaking stops. buying it with such low miles I figured I wouldn't hit anything too expensive and the owner before me was a sweet older lady that didn't drive a lot.