Omega B – Wet in passenger footroom, cause?

In the passenger footroom (km-low Omega with 114tkm) under the carpet is constantly moisture. The windshield has already been re-glued and sealed. The two water drains on the left and right are continuous, i.e. the water runs through perfectly. I have to refill coolant regularly lately, although I move the vehicle almost on Sundays. The climate has changed. There is no noticeable loss of performance of the air conditioning system. I noticed a small puddle last time in Hungary, when I had a sham change. But did I do this as from another vehicle. Probably not. It indicates, as others wrote, in the direction of leaking heat exchanger. How do you proceed in such a case? To FOH for troubleshooting? Or to look for yourself? What can I check myself without the need for And what about the “radical” method of another user I have read of, who has simply replaced the plastic layer at the bottom left of the middle part of the dashboard, where he cut the foam to get through to the heat exchanger? Is that possible?