I have had my Model X for a few weeks and have a little over 1000 miles on it. Today I pulled into a parking spot and hit the curb adjacent to the parking spot. My tire split along the side and had to be replaced. The cost for the tire was $350 plus labor. Maybe I hit the curb on just the magical angle, but I was going like 5 Mph. I can't imagine that these tires would hold up on anything off road. Is anyone else concerned about tire quality? Also, I'm thinking that it would be nice to have some kind of tire guarantee or insurance service. Any ideas?