Hi all we have an 07 with about 40000 miles on it we reciently (DEC) had a nail in one of the tires and had to have it replaced because the nail was in the sidewall i just looked at the tires today while we were waxing it. and the tires on the left side are consistant wear for 40000 but the front right has all the center of the tire tread gone. the pressures are right where they should be, and the car does not pull or vibrate. could this be due to only replacing the right rear tire then I had the nail issue? or could it be something else? Oh this is a AWD 07 EX. All highway driving.