I've been getting a mist through the vents and fogging up of the windscreen sometimes. I doubt its the heater core because I cant smell coolant and there isnt any coming through the footwells. theres only a musty dirty smell. I've heard this is caused by a blocked drain pipe but no one has said where exactly it is. I know it is around the gearbox but I had a look and cant see any pipes ending around there. the car is a VT 5L manual if that changes anything. also I was told that it can be blown out with a compressor but I'm not sure about that because it would come from inside the dash wouldnt it?