Mold on the interior of my back window?

I noticed the other day that I had some mold on the bottom of my back sliding window, I cleaned it off with some vinegar but its all hard and black brittle underneath what do need to do what is causing this? Not sure if its unrelated but Ive started to get these brown stains all of the flooring and the upholstery.

 

Leak from third brake light gasket?

 

The lights on the top outside though

 

Leaks around the gasket and into the headliner. There’s a recall campaign for the gasket replacement. There’s a couple of threads about it on TW. People find damaged headliners, carpeting and upholstery. Just a thought.

 

I found some of the threads buy mine is a first generation does it look like my window is coming out at bottom exterior?