your design is fixed camber/caster - your bushing is shot, your tire is shot from the inside, you have found your fault already.

MB springs are not that poor that they will sag at young age, I had similar wear on my W124 - the fault was ball joints, they were a bit way to sloppy for any standard.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)