Guys, correct me if I am wrong. My understanding is that if you don't track your car, Motul RBF 600 would not be a great idea unless you chage it out more frequently than a DOT 3 or 4 "standard" fluid. I thought that it was more hygroscopic; but, I haven't really heard specifics on how often it should be changed if not tracking.
For a street-only car, I would think that Valvoline DOT 3&4 synthetic (blue label), or Castrol LMA would be good.
But, for sure, bleed all of that old stuff out of there in the process of putting the new in, like Ron says above.