Man, it took me about 5 minutes to stop laughing! (sorry)
Disconnect the battery.
Take a thin piece of wire, about 20 AWG. Copper should work OK.
Bend a small loop on one end (about 3/8" diameter)
Get some sticky stuff (I have some 3M that I use, stays sticky for a long time).
Go fishing!
If you are lucky, they didn't slide down too far.
(BTW, this works well for defroster vents/ducts too.)