My Stang has this weird vibration at like 1,600 and 3,200 rpm when I first start it up. This happens when the car is both warm and cold, free revving, and under load. You can feel this vibration throughout the entire car at these two RPMs. But after about a minute of driving the vibration will go away. I looked it up and there seems to have been a recall with the S197s doing this, but nothing about our cars. Any idea?