Rear Suspension problems of the 2006 Toyota Matrix

Purchased certified pre owned - (leased) 2006 Matrix 27940 miles 7/26/08 - on 11/12/08 32955 miles after oil change dealer wrote : "tires are wearing funny - aligned at n/c did not rotate rht rear cupping - 3/25/09 oil change 38632 - dealer wrote - rotate tires if needed - last time in had tire wear issue needs tires has 1 good tire on car on lf. Apparently this is a problem with Toyota - haven't contacted dealer yet but will after reading complaints. I don't know if the after market shim fix will void my extended warranty or not. . . . . .

Excessive tire wear due to design flaw/workmanship of the manufacturer. The rear end alignment is not adjustable, and was way off from the factory. Had top replace the tires at 15k miles due to cupping caused by camber/toe in way out of spec. Toyota said that tire alignment was well within design specs. Drove for 15k miles on second set, was told by tire specialist that 2nd set of tires (not same as original) was also cupping, and that the problem was definitely in the alignment of the rear end. Had to threaten Toyota with a lawsuit before they admitted there was a problem. They added shims to car (I had to pay for parts), but flat out refused to re-imburse for ruined tires.