I got the letter too, it says bring it in at your convenience, I called and waited weeks to get booked in, mine had the problem but they do not hold the spares so have to order them in. Weeks later they call me and say the spares are in can I get it booked in to fit it. So asks to have it done the next week only to be told, they can't fit the part if the bike was not checked for the fault first, so I explain that it was checked two months ago and did haved the fault but could not be repaired as you do not hold the spares which you have now told me you have

The answer to this was, yes but as it was more than a month ago it has to be inspected again to see if it has the fault before we can authorise a repair

maybe I'm wrong and BMWs have the technology to self heal, but what's the betting I turn up next week only to be told, it needs the part but we have to order it in and then I wait a month to be told they can't fit it as it needs to be inspected for the fault first and so we start the whole circle again

Hope you all have better luck than me if you need the part replaced.