Ok, here's the thing. I'm a mechanic at a tire shop in KCMO, I do my own alignments on my cars('88 TurboZ, '03 350Z). I've played with the alignment on my 88 for months. This is what i found out: when the shops do the alignment, they have to raise the car up off the alignment rack to rotate the tires to compensate the alignment wheel sensors. When they lower the car back down on the rack, all the wheels are not in they're rolling positions(the top of the tires are leaning out like positive camber). Then they proceed to align the car with the tires in the wrong position! In the alignment manual it tells you to bounce the car to settle the suspension. Well that works for the front tire because the fronts are on turntables but the rears are not! I had to roll the car back and then forward to get the tire in the rolling position then adjust. had to do this about a few times after each adjustment so the tires were in the forward rolling position to get a true alignment reading. Most shops don't do this because its to time consuming(almost 2 hrs from the time i drive on the rack to the time i drive off)!!Maybe this helps. Got my 88 z handling almost as sharp as the 350Z.