I'd say you did well to get 19K miles out of them. Most folks indicate rears wearing out in the 8K-12K mile range. Items that impact tire wear are driving style and vehicle alignment. If you looked at the old rears, I imagine the tread block on the inside were fairly low, no? This is because of the desired negative camber that helps the car corner so very well. Its the price to pay to enjoy the drive!
