96 E 320 Alignment Issue

[c_ron]

Shortly after buying my E 320 last summer the inside of my RR tire rather quickly wore down to the steel belts, while on a road trip. I noticed some thumping, got off the frwy and to a tire shop and bought another Michelin XGT. When I returned from the trip a week later, I had the car aligned by a reputable shop that does lots of MB alignments (having described the tire problem above). I was allowed to watch the process and was told that there was hardly any 'tweaking', front or rear, that needed to be done. I accidentally noticed just today that the right rear tire has again worn down to the steel belts, again on the inside.

Anyone have experience aligning this particular model? What should I tell the alingnment shop, other than the above?

Thanks for any help.

R