Skoda Octavia Heater Matrix Problems

Hi all,a mate of mine has a 2007 skoda octavia 1.9 tdi ambiente,The problem started a few months ago thus far he has spent over £1100 yes £1100 trying to solve it to no evail,i will describe the problem then list parts and repairs so far....

water is coming into the passenger footwell from the Pollen filter housing. The filter gets wet for about the bottom inch or so.The scuttle tray and drains from from the engine bay are clear and dry and I cant see where water can get into t...