Yeah I wash the car to clear off any sediment that rain water contains; however the car has hardly ever seen rain since it's garaged. I haven't used any "special" brake fluid in the FD but in my older BMW I ran ATE Super Blue Brake Fluid DOT4. I don't think you need special brake fluid unless you're racing and your lines get hot. As for coolant I have used any brand from my auto parts store. Sorry I can't speak to tranny fluid.

 

I agree with the fuel dilution being a problem if your mixture is too rich. That is not good for the turbo oiling.