This isn't about losing a radio or its parts, but it
is about misplacing things, so I guess it's kinda-sorta on topic.
Speaking of misplacing things and not finding them for months or a year or more(!), I had an experience like that a couple months ago. I had been looking high and low in my apartment for over a year for my letter opener, but couldn't kind it anywhere. Looked in drawers, under furniture, cabinets ... couldn't find the darn thing for love nor money.
Then, about a month ago, I found it -- it was in the small space between my stereo system and my desk! It is now in my desk drawer, where it belongs and where it will stay, from now on, when I'm not using it.
For Sandy: I'm sure you'll find that speaker somewhere. I don't know how large or small your garage apartment is, but it might be hidden away under something or in a corner, etc. Your wife's brother may find it by chance one of these days and surprise you.