oldpaint

Hello,
We bought a used 2004 slk230 about a month ago and really never used the air conditioning or had top up since we've been in a basic drought. yesterday my wife drove the car with air on and top up in some rain. Water has leaked out of passenger footwell duct and also out of the filter underneath the glove box onto the panel, soaking the padding and dripping onto the carpet.

I've searched various forums and people talked about drain for the plenum being plugged but I can pour wather into the cowling and it drains out of the big drain hose onto the ground. I used a hose to pour water all over every area of the top, cowling side windows etc and found no leaks so I don't think it is rain coming in.

The only other thing I can think of is that air conditioner is not draining the water properly. I could reach up into the air duct where the cooling coils are and felt some water. Where is the drain for this area and is there a way for me to see if it is plugged?

Thanks a bunch.