whenever something falls into the black hole abyss or the engine compartment as well, I ALWAYS get it out. i don't know what the hell could be happening in there so i waste the extra 15 minutes to search through and find it. don't worry, it'll be worth your time and you can sleep easy.

if you can't see it with a flashlight, then consider getting the extendable magnet. you can find them at any auto store. it's just a telescoping magnetic rod that can pick up tools or any metal near it like screws. works great. try it out sometime, you'll have a lot of fun.