Brake fluid

[gt6493c@prism.gatech.edu (gt6493c FLUHR,ERIC J)]

I have heard a little bit on Audi's 'special' mineral brake
fluid, but which cars use it?
Specifically, I have an '85 Coupe GT (which, BTW, has a 110hp
engine...hey, I'll take all the hp I can get when it is that
low) which I just acquired 1 1/2 years ago and have been using
Castrol Dot 4 brake fluid in.  
I know I could probably find out the answer by looking in the
owner's manual, but I'm just a little lazy (besides, I like getting
mail).

Also, I worked on the front end this summer.  I installed front Boge
Turbo Gas struts cartridges, new strut bearings, 1 tie rod end, 1 ball
joint, and 1 inner and 1 outer CV joint.  
Man, what a difference those struts/strut bearings make!  Before, the car
wandered a bit on the highway, now it is rock solid.  It feels much
better initially in a turn, much steadier.
Another question:  Out of the 4 CV joints, only 1 appeared significantly
worn (the pass. side inner).  I replaced that one, as well as one of the
outer joints, because I had been hearing a clunking noise since I bought
the car.  Unfortunately, the clunking noise was not resolved by
the new joints (it only happens on sharp turns, generally when backing
out of a space and then going forward again).  Is there something else,
maybe in the suspension settling, that can cause this sound?

Later,
Eric