I run ValvolineProSyn in my street cars/trucks or the cheapest stuff on the shelf with the highest wet boiling point. although when I could get super blue I did use that in the M3.

anything more is an absolute waste of money in anything other than in a race car!!!

with the way brake fluid absorbs water you should just be flushing it every few years anyway!

now in my Formula Continental I used nothing other than SRF.