Aryza and Van Helden -
check out the thread that I started recently called "bad tires or bad wheel balance". I am chasing a wheel balance problem, as well, and it's clear to me that my problem is bad tires.
I also have Goodyear Regatta II's.
The shop is replacing my tires (thank God), but my problem and yours if you get your tires balanced on that Hunter wheel balancing machine Hunter GPS 9700.
Click on the link and see how the machine works.
Enter your city, and a whole bunch of shops were listed that use this machine.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".