My coolent level light  flashes randomly but about 95% of the time.  I've
taken it to a vw qualified machanic(not the dealer) to no prevail.  I have
flushed the system and bled it, chaged the thermostat, changed the coolant
level sensor in the resevoir tank, had another sensor replace under
dashboard, the heat level sensor on thermostat housing replaced and checked
for grounding problems.  The machanic said it might be in the gauge it self
but isn't sure.  I don't wan't to spend the $100 plus for the part and have
it not work.  
My heating system works terrible.  The back heater works better than the
front but it fogs up the windows and smells bad.  The front heater will
smell some times.  It only blows hot 1/2 the time and the defroster fogs the
windsheild more the it helps.  I had the sysem pressure tested for leaks but
we lost no pressure and saw no leaks.   It seems to me that it is the
heating cores.  The back one seems easier to chang than the front. The front
looks like a nightmere to change.  What do I do next?  help!
              COLD IN SEATTLE
Fred