refilling my AC fixed this problem for me as well.

mine was so bad that when the AC kicked on and the pavement was wet it would break the tires loose. kinda disconcerting at 75 on the highway.

good luck.

for sale: E0 (98) Silver Frost SVT/Contour http://contour.org/carprofile/carprofile.cgi?a=display&uid=667 wanted: front SVT bumper mesh, 01/02 S4 avant, nogaro blue.