Replaced my cabin air filter on a 2018 F-150, went smoothly - this part rolled out onto the floor and for the life of me I can't find where it might go or what it is for.

 

It’s probably a bumper/anti-vibration cushion from where two plastic surfaces meet [which would otherwise rattle and/or make a 'snap' noise when they are brought together] Think on the glove box door, for instance.

 

Is it one of these parts?

 

Same thing happend to me. I believe it's part number 3. Take off the glove box and you'll see where it goes.

 

Thanks guys - no luck yet - went to the parts desk at Ford and also body shop. They have no idea, so I'm putting it in the glove box for now

 

I did the same thing and finally figured out where it came from. It goes on the back of the tray (#5 in the picture) There is a plastic post that it goes over and then that lines up with a hole in the dash.

 

WOW - Thanks so much! - that was it.