You all have alignment issues or worn components or both. I've learned that dealers don't really seem to know how to align a car well. When we bought our 202 new, we went through two sets of pirellis in no time.
I finally brought it an independent tire shop (not a franchise) specializing in alignments and suspension reairs. 146000 miles later, I've only bought three sets of tires, and the tires on there now have at least 25000 left on them. I've had to do one alignment after I replace the lower ball joints and outer tie rod ends.
2001 E430 Sport
1997 C280 Sport
1986 190e 2.3 16V (2)
1968 W30 442
1988 "Plain Vanilla" 46' Cougar US1 Triple Blown 572s