There appear to be three separate drains on the Cayenne, the sun roof, the outside dash, and a air conditioner drain under the glove box that all feed through the same mechanism of the firewall to the same plug below. My sun roof and outside drains, as well as, the plug underneath have all been cleared of debris. That is somewhat well documented. However, the air conditioning drain, and hose, are not as well documented. I am still getting a fair amount of water into the passenger side foot area. I am pretty sure at this point that the hose leading from the air conditioning unit drain under the glove box is beyond repair. But I cant find any DIY info about rerouting or replacing it. Can anyone here help me with where this information might be?

 

There's a flap at the end of the hose that gets stuck. You can get to the hose pretty easily by removing one screw to release the panel underneath the glove box (there's various youtube videos showing how to do this). Then you need channel locks or hose clamp pliers to release the hose from the AC condensation tube. You do not want to remove it entirely from behind the firewall because it is very difficult to reinstall through the firewall. I used a blunt stick object to push through it gently and clean it out and exercise the flap. You could probably use a strong straw and also blow it out. I then injected water gently into the hose with a blunt syringe (turkey baster or ketchup bottle nozzle) to check that the water would drain correctly into the wheel well through the cowl drain hole.

If the flap keeps getting stuck I guess you could always run a pipe through the hose so it keeps the flap open then use a worm clamp to secure the pipe. You would run the risk of critters or debris crawling up into the AC though.