I have about 600 miles on Continental DM non-run flat tires (from Tire Rack). It has transformed the car (a 2006 3.0si) into what I always knew it could be. After the original Bridgestones were worn, I went to RF Michelins. That was a significantly better tire. If that was one notch up in comfort and noise reduction, the new Continentals have to be two or three notches better. I built my own repair kit using Slime products: a bottle of their liquid and a compressor.