i don't have a tire clearance issue in the rear between the top of the tire and the body; mine is touching the body in front of the wheel on one side. not horribly evident, but it does touch, and the wheel is otherwise centered in the opening. ahh, well. so far, i have to say it went together without incident, even with the Pacer six transplant and the widened seats. i WAS going to clamp the rear of the interior tub to the chassis plate and glue it, but now i think that would have pulled the rear wheels too far up. the rear of the chassis IS a bit too far down, and the next one i build will have that corrected with some styrene glued between the tub and chassis.
it doesn't really build up like a typical '70's kit; i remember most of them having vague locating pins/slots to deal with; this kit has definite interlocking features that build up pretty solid if you think it through. darn sight better than, say, the AMT '68 Torino GT kit....