That's why you always buy the wheel and tire replacement package. I do it with all my cars and have probably saved 20 grand while only spending about 5,000 on the packages. I have a deal on my Cayman S that replaces the tires even when I WEAR THEM OUT!!!! I bend a rim, I get a new one. I run over a nail, I get a new tire. My tread is thin, they replace the tires FREE. It cost about $3500 when I bought the car, but I already have replaced the two rears and don't see why I won't get a return on my investment even if I only have the car a couple of years. I did the same thing with Cadillac and had to replace one of the run flats already.......total cost $0. I think you can purchase it even after you buy the car, you should contact your dealer.