Everything has been checked, all carpets/soft furnishings bone dry, all vents/drains clear.
Car will be perfectly OK most of the time, but if it gets damp .. mist/fog/rain and coldish .. below 5 .. then she'll steam up ...

Sticking demist on clears it, but turn demist off and after 5 minutes its back
Crack the sunroof a fraction, or open a window a fraction and all remains clear ... which is why I was thinking recirc flap....
Playing around today after changing oil / filter .....
Air con compressor runs fine and switches off when eco selected as it should .. now going by the two "gas connections" ..... the "thicker" pipe, although it gets cold(ish) does not seem to get as cold as it used to.... the "thinner" pipe stays quite warm.
Question then ... if the aircon needs a recharge .. would a low efficiency cause this steaming up problem

The aircon is "supposed" to cool the air to remove moisture before heating it back up as it enters the cabin ... if it's not cooling enough .. is the air still "moist"

Any ideas ??
I'm thinking of just taking it to an aircon place and getting it checked .....