All BMW dealers are supposed to carry a replacement tire in stock at all times in the original size for the BMW vehicles that do not have a spare. I don't know how many actually do what they are supposed to. As you say, you'll probably end up paying retail for it as well.ard said:I've often thought about the scenario you suffered. It is compounded by the likely fact that, when the $tealer opens in the AM, they will need to special order the tire anyway! another day or so, then charge you $400 for it!
Unfortunately, unless you are 100 miles or more away from home, there are no "replacement" vehicles unless you can get one from the dealer (who in this case is closed until Monday morning).