I replaced OEM Dunlops with Conti's. Love them, and cheaper. I do however have 3rd row seat, so no spare. With BMW Assist (or AAA or other auto support service), I really don't see it being a big deal. No flats (yet). Conti's had been on nat'l back order, but I was somehow able to get a couple in when Discount Tire put in a formal request with Conti. Conti's supposed to last much longer. They are definitely much quieter and are a better ride. I really don't feel a difference in response, etc, and not sure you really would unless you were on a track, which I'll never be. And the look is just as good or better than the Dunlop. Just my 2 cents.