Excellent detective work and solution,
oldskewel! I'd replaced a few rear control arms/links over the winter on our E53 to resolve an inside rear tire wear issue, and only recently took it in to two different alignment shops. The first couldn't set the LR camber (lower rear eccentric of each rear corner), and I actually watched as they spun the eccentric around with a long crescent wrench without changing much of anything (ultimately made the camber worse). The techs didn't understand, claimed it might be a "bad bushing" despite no play, and gave up after exhausting themselves (bolt turned but with obvious difficulty). Then at the second shop yesterday a different tech at a different shop was spinning the RR toe (upper front eccentric of each rear corner) bolt with a monstrous impact wrench but again without much change and a similar conclusion of "random", although neither could detect any other worn out components. I'm going to put it up on ramps tonight to see if damaged stamped eccentric shoulders might be our problem too. Or will I need to jack it up and remove the wheels to see all of the eccentrics? When I had it up on a self-serve lift last year for the last control arm replacement, I seem to remember that there were actually three (3) eccentric bolts per corner, but both shops claimed only two (one for camber, one for toe, but none for rear caster). If there are actually 3 as stock, what's the 3rd eccentric bolt actually for (lower front of each rear corner, IIRC)?