I don't think DOT 5 is a good idead and I'm pretty
sure that Audi strongly advises against DOT 5.
Doesn't DOT 5 absorb water very quickly, must
be frequently flushed and is really for track use only
and has no real benefit on the street?
You may be right about it not being recommended.
It is however highly hydrophobic. You may be
thinking of DOT 4 which is the high temp racy
face stuff. DOT 5 is more for water protection.
At least that's my understanding. I would happily
be corrected if I am wrong!