[Rick Parker]

This was covered at length a couple of years ago. It was determined that certain brands of tires were not "Round", and had radial runout which was unable to be corrected without changing tire brands. Our cars (in general) are more prone to this because of their light weight, undampened steel U joints used in the steering columns, solid steering wheels, and often times the use of Heim joints or metallic bushings at the pivot points and shock absorber mountings throughout the suspension. Its the "Nature of the Breeed".
Many of the cars use a Mustang II type front spindles. When combined with knock off adapters and width wheels we typically use, the scrub radius is put in a very unfavorable spot.