Graduated from a '98 A4 2.8Q (which got rear ended and written off) to an '06 A6 4.2Q a few weeks ago. Wow, what I've been missing - what a seriously fun car (even though it has AT)!

Anyway, as I was taking the belly pan off to investigate a small oil leak, I later noticed a small part on the garage floor - my guess is it may have been lying in the belly pan, as that's all I removed from the car. It may well have been something that was accidentally dropped and left there, but thought I should reach out and see if anyone recognizes it and make sure it's not something that should really be installed somewhere on my car... No part number or markings visible except for number "14" on one end. Attaching some photos. Any ideas?

 

That almost looks like a bushing that you'll find in between your hood and the chassis in order to prevent any rattling, or perhaps for the air box where it mounts to the chassis.

 

Thanks, Nebuchadnezzar - it was indeed one of the two rubber mounts for the air box where it rests on the chassis!

 

It's not a mystery bushing.
It's a grommet, and a seating for your air intake filter box.