I get rid of the run the flats tires and get regular performance tires right after I get a new BMW. I do not carry a spare! I have a mobility kit which has slime like stuff and an air compressor. I also have a small plug kit that can plug a tire. I have had 3 BMW’s this way since 2002 and never been stranded. I also have a cell phone I carry with me. However once and a while I take some mountain roads with no cell service so my backup there is the BMW assist button. Since 2002 I have had 2 flats but only had to use the air compressor to get somewhere it could be fixed.
A few other things about run flats: If you drive on a flat run flat it is supposed to be non-repairable. If you need a run flat in emergency you are going get jammed by the price. You can get 4 performance tires for the price of one or two run flats.
2015 M235i - Estoril Blue - 6 speed - Black Lather - Cold Weather Package - Premium Package - Harmon/Kardon Premium sound