Vibrations
I went to the track Sunday; on the way down, we did anywhere from 70-140... everything was fine.
Got to the track, dropped the tire psi down to 20, and the car performed just fine.
On the way back home, got on the freeway and as soon as I hit 80, I got a nice vibration. I could feel it in the shifter, and it acted like a massaging chair on my back. I drop down below 80 and it fades away. It was definately more prominent going straight ahead, and on left turn bends, but seemed to be a little less noticable on right handers. Once I got home, I aired the tires back upto 40psi, and it got a little better... not perfectly back to normal, but definately better.
Did I throw an inside wheel weight?
(This is on a '02 WS6 with freshly mounted tires, by the way.)

