Thanks for chiming in Damon, I appreciate it. As AMGE63 notes above there is no question on replacing a bulged traditional tire but my statement was on bulged run flats. I know driving on deflated run flats kills them but BMW told me that doesn't matter because punctured runflats are never repaired but must be thrown away.

My 335i has 18" runflats and I noticed a very slight bulge on one shortly after buying the car. I returned to BMW who of course said I must have hit something and offered to replace the tire at full retail plus labour.

I asked about the reinforced sidewalls that allow these tires to be driven on when fully deflated and the rep said that doesn't matter- if they bulge they need to be changed- same as normal tires.
As I mentioned in my earlier post, I don't understand this logic. If they are safe to drive on when running without air, why aren't they tough enough to drive on when properly inflated with a small bulge?

With what I've learned about these tires, when it comes time to replace them I'll be going over to traditional tires and buying a emergency flat repair kit.