2010 Buick Lacrosse cxs the other evening as I was driving home with my wife a little before sunset at about 30 mph I heard a thump and assumed I had hit something. Neither my wife or I had seen anything in the street. I continued to drive home (3 blocks) and the car drove normally - no change. When I got home I examined the front of the car (drivers side) and saw nothing unusual but noticed the back right tire was flat. I got out the jack and changed to the spare. Upon looking at the tire I found no apparent damage to the tire other than it was obvious I was driving with the tire flat. Upon closer examination of the wheel itself I found a gash in the wheel about 6" long and elevated up into the tire area over an inch. Of course all of the air escaped through the gash - no blowout. Went to the dealer (3800 miles on the cxs) and they determined I had hit something in the street - no warranty coverage. Cost for new wheel and tire - $1002 went back to examine the road (no potholes) and finally found a rock off the side of the road that apparently caused the problem. It was a rock, flat on both sides about 2 1/2" thick and about the size of a red brick only oblong. Have no idea how it hit the back tire and not the front. I am convinced that had the tire been an older 15" or 16" tire the tire would of absorbed the hit and not damaged the wheel. Of course it may have blown a tire but the wheel would of been in good shape. With the roads becoming so bumpy with potholes I now worry about hitting a bad spot in the road and having the same thing happen again. I carry a $1000 deductible insurance so insurance will not be involved. (in 50 years of driving I have not had an accident that was my fault or any other damage to one of my cars - so I carry a high deductible). Just a word of warning to those who have the 19" tires (and probably the 18") that a bump in the road may do more damage to the fancy aluminum wheel that the tire.

- San Jose, CA, USA