Lesson: always regularly drive and search all the cars in your family's fleet.

All my children learned on our 240s and the two still at home still drive them (we have four counting my wife and mine).

Just wanted to share this recent "discovery":
I probably should check them more often but, since my daughter was out of town for a few days, I drove "her" 240. While putting some groceries in the trunk, I saw beneath the spare tire the corner of some unidentifiable object. Upon retrieval, which wasn't easy since I have a full sized spare in there, it appeared to the original gas cap, twisted in more directions than I thought possible. With optimism and hope I opened the gas filler door and....my hopes were dashed - no [replacement] gas cap.

Thanks to the cellular age, I immediately contacted my daughter a few hundred miles away and got the typical "Oh yea, I forgot to tell you...." and "...it just happened..." The Kragen is less than a mile from our house but apparently it wasn't convenient for who knows how long. I didn't bother to ask how it happened to be in a nearly unrecognizable shape.