Water in the drivers footwell

2.0 HDI Multispace Forte 2005.

There's no sign of a drip anywhere, but there's enough water in the footwell to get a good "squelch" when you depress the carpet.

Things I've checked:

Pollen Filter  - a few leaves and a bit of dirt but dry (and in the passenger footwell anyway).

Scuttle panel and drains - water drained slowly and would submerge some of the grommets in the bulkhead, pulled out a lot of rotten leaves and it certainly seems to drain quicker now (faster than I can pour it in with a watering can anyway).

Sunroof - it's got the fabric sunroof, but there are no signs of water getting past the seal

Door seal - I've had the trim off and there was a cut in the membrane where a smashed window had obviously been replaced (obvious because the smashed window was still there in a million pieces!) But no evidence of water inside the door or on either side of the seal. And the seal on the body is fine (given a smear with silicone grease to be sure).

The coolant level hasn't shifted, surely if it was the heater matrix and this much water I'd be having to top it up?

Things I need to figure out:

Where does the AC condenser drain? I think I saw it inside the pollen filter housing on the passenger side.

Where is the heater matrix? If it's not the thing I assumed was the AC evaporator in the pollen filter housing.

There's always the possibility it was the scuttle drain and it's just taking a long time to dry out. I did 250miles yesterday with the heating turned up and the AC on, and whilst it's not as bad as when I first noticed the problem a couple of weeks ago it's not as dry as perhaps I thought it should be after 5 hours of t-shirt temperatures. There was a brief rain shower, but not a substantial one.

[edit]

Does windscreen seal look a bit ropey?