Unstable Z
Wide, low profile tires will follow groves in the pavement. They do "evil" things on pavement that is not flat and smooth. Ruts from tractor trailers, grooves in the pavement and the general uneven condition of most roadways (they all have "dips" from traffic running on them) can cause F-bodies (most anything with wimilarly sized tires and wheels, Mustangs, 300ZX's, etc) to wander around. Some of it is normal, but it is hard to say about yours. You may have replaced the stock Eagle RSA's (Really slide around?) tires with something with a much stiffer design. Doing so will increase the responsiveness of the steering and may make the car feel nervous, this will be more pronounced over uneven pavement, etc. If there does not appear to be any slop in the steering linkages and it just started since you replaced tires, it may be the tires, or the tires are causing you to notice an alignment that is not "correct" that the other tires didn't seem to show. What tires did you remove and what did you replace them with?
Kevin


