Yeah that. Mine didn’t make it to the floorboards but it got under the backseat and caused mold on the seat cushion. The body shop had to fix the vent and replace the trunk carpet and all items in the trunk as well as the back seat bench. It was a total pain. My insurance paid for it, but it would have been like $2k out of pocket due to all of the damage. I noticed the issue when I went to check the spare in august and I had a bad allergic reaction opening the spare compartment. Turns out there was mold on the carpet under the spare.
You’ve never heard of these pressure vents because they don’t usually fail. I guess it’s possible if it was in a collision. But even then, cars are rear ended all day long and my body shop said they’ve never seen this issue due to minor bumper repairs. I think it’s just a bad design. The water runs down the back quarter panel and gets routed over the tail lights and then over these vents before draining out of the car. If the gasket isn’t 100% it leaks into the trunk behind the carpet and ends up under your spare tire and subwoofer. Then when you drive the car it can slosh forward under the back seat.