It's the negative camber, but that's a little too much wear for 12K miles. You could also dismount the tires an swap them from side to side. I know you're not suppose to, but the alternative is getting new tires pretty soon.

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2003 4.6is, Saphire Black on Black with Aluminum trim, Comfot Seats, Loading floor, Nav, TVonNav, Focal Utopia's in front, with Rainbow's in back, Helix 5 channel amp. ACS pedals, Aluminum steering wheel trim, X-pipe