I had my tires switched at about 12000 miles. Nissan did an alignment also. Then at about 18000 miles the tire roar started to come back. I took my car to Brown and Brown in Mesa Az along with the thing Nissan sent me in the mail. Now from looking at my tires there wasn't that much wear noticable, but you could hear it. They gave me new front tires, with no questions asked. Anyone in AZ with this problem should check them out. Great service, it took 2 days but they gave me a free rental. I am very satisfied and glad Nissan is taking care of this to some extent, although I would rather them have a fix for it. Anyone know if a new suspension fixes this problem.