I took the warranty. $1500 on 19in tires and no deductable. After two weeks of driving, one of the tires developed slow leak. Took it to the dealer and they told me that it had a nail puncture. They replaced it under tire warranty.
I also never had a nail in 20+ years and was very surprised to discover the nail puncture in new car. My gut feel is that these RFT’s are more susceptible, but everyone keeps telling me it just a coincidence.
http://x3.xbimmers.com/forums/showthread.php?t=698294