In the USA market, you can simply go to any of the nationally advertising tire sites and input the tire sizes you need (square or staggered)…then select what type of Tyre you’re looking for (in this case, run-flat)…and get a list of tires. From that list, select the tires that meet the speed and other specs required for a BMW…you may even be able to input your model/model year/etc and then select tire sizes and type of Tyre you’re looking for.
Have you tried that for your market? Here, you can also select alternate tire & wheel sizes, too.
Example: click on any of the links below and input your vehicle and tire size regardless of you being in a different country/market. You can still pull up compatible tires in either runflat or non runflat…then shop for that tire in your country/market.