Planning to use some disc brake quiet either have my shop put it on the day before or do it myself using some Loctite Disc Quiet Stick
https://www.ecstuning.com/BMW-E82-13...3.0L/ES240432/
I've never heard that racing brake fluid (like RBF600) can't be used as DD. I change mine every 2 years and its pretty dry climate here in NV. I used it for my motorcycle trackbike but I did change it annually before the start of the season. How about using Motul 5.1 instead of Dot4?