I’ve had a problem with mice getting into the heating/AC ductwork on the Chevy Express HVAC part of my Forester while it’s not in use. When the heat or AC in the cab was turned on all you could smell was mouse pee. I tried flushing the cowl area with a bleach solution, Simple Green, Lysol and a bunch of other cleaners. It would cut down the smell but it wouldn’t take it all away. I finally decided to take things apart to clean it all and see if there was a way to block the mice from getting in. Figured I would pass this along in case anyone else needed to deal with the problem. I made a video of what I found and what I did. I apologize for the amateur quality of the video, I made it with my phone.