Easy way to check drainage locations for aircon?

I know there is talk of checking plenum which I've never looked at myself but just wondered besides getting too detailed if there was some quick and easy ways to check for any blockages in any obvious locations. I'm on a BLT

I don't think I'm getting any moisture in the passenger but I've done the door seals fix again and again; I don't have dripping wet carpets at all but the other day did notice some collection of annoying condensation again at bottom of screen for a couple of days ?

Also checked my boot I don't believe I have any ingress there either.

Just would be useful to know where to check in case there is any leaves build up. I saw a thread somewhere where people were talking about a drain hole under the wipers but haven't a clue where exactly they mean