Son of a... so I had the right idea. Just wasn't targeting the right thing. I was facing the other way.
Viewing post in Need a Hint?
So - the air filter isn't the only thing. Notice the other seats have the same "storage" slot - one will have nothing - the other three have items.
One of those items is for eating.
And when you eat at a dinner table, you are left to take a seat.
The solution crammed into one long word:UsEthEsPorKthInGtOCuTuPthEleFtfRonTsEaTaNdItWiLlReVEaLsOmEthInG
Put a strike through to make it harder to read so you don't accidentally get it revealed before trying something.