heating woes

[betobenz]

Hello All,
I have owned a 300tdt wagen for just over 3 years now. Wonderful car. Is this perhaps the best wagen ever made on the planet? The Heat however has always been a bit strange and recently it's getting to the point where it's starting not to cooperate at all. This is a problem as today in the Boston area where I live,it is around 5 degrees! This problem happens even with the engine warm. The heat works well on low stting. I put in ont auto and it starts to work satisfactory on automatic setting. Then after around five minutes the air is coming out cold. So then I put it on low again and warm air comes out. I try the auto middle setting again and it starts out warm then within 40 seconds becomes cold again. Sometimes the auto setting will prooduce heat lognger. Sometimes using the front deffoger will help. I then go on the highway and go at higher speeds. This aggrevates the heating system now its all pretty much just cold air but keeping on low will start to get the warm air a flowin again. ABout 10 minutes later I exit the highway and drive slower. Now it improves somewhat.
Does anyone know what is wrong here. This is a problem that has gotten progressively worse each year and now is fast becoming a big cold problem!
I have the push button type climate controls. IWhen it's cold and winter, I use only the hot setting on the little finger roll wheel. I only use the econ set button not the AC buttons. Using the AC buttons does not help things. ANY easy solutions here?