I have been monitoring my coolant resevoir for the past few months and
have
noticed that it hasn't been going to the max line after driving for a
while. It used to be it would fluctuate
between the min and max level (usually at max when hot) then back down
more towards the middle. Now, recently it has been sitting at the min
level whether it is hot or not. It may go up a hair when hot but nowhere
near the max level where I feel it shold be when hot. I have been checking
the ground, but there are no leaks, nor am I blowing any white smoke. With
the long coolant lines in our vehicles, is it possible that it could
evaporate in a sealed system?  I also do not smell coolant outside the
vehicle when it is hot. The manual states to add coolant when it gets
below the min level, but not to check for leaks or take it in. So, by the
manual saying to just add coolant seems to me VW expects loss of coolant
somehow.
Any suggestions???

-steve-