To top up I have used plain tap water for 6 plus years where I live. Have to add a cup or two about every 6 months. It does not get very cold and our water does not have a lot of stuff in it. My local dealer uses tap water. But distilled water is good.
If you do not have the new style blue cap that ends in 01 you should. It seals better. If the tank leaks it is a known problem.
For coolant.
http://www.renntech.org/forums/index.php?showtopic=3772&st=0&p=18113&
Porsche has started selling coolant in 1 gallon jugs instead of just the 1 liter containers. It says made in the US and I hope to figure out who in the US is making it for Porsche.
A mechanic I know said you can mix the Porsche coolant with the Audi blue, but not pink.
