You have a good point about the overusage. Although, they haven't used it since the second season, which I felt was sort of symbolic at that time when they finished the YED storyline, sort of conclusive to that part of their journey. So whenever they end the show, it would be a nice callback to use again, make everything come full-circle.

I hope the Impala already "died" or something like that because it kind of depresses me to think about it "outliving" them and who would take care of it and what would happen to it? :(

Maybe Bobby could take care of it? lol, even though "Swan Song" was kind of cheesy, maybe the "passing it down" is kind of symbolic? though I would hate for the entire Lisa/Dean/Ben thing to be that Dean passing the Impala to Ben because, fuck that shit Ben doesn't deserve the Metallicar and her glory, kthxbutno

But realistically, I think the show will probably end with either Dean and Sam dying or riding off into the sunset, with all the rest of the characters dead. :|

I would hate to think of Bobby being dead. ;___; Or Castiel, for that matter. Which makes me think that Castiel will either return to Heaven and meet up with Dean and Sam after they have died as well. Or something, idk. It's really depending on whatever is gonna happen when the end does come.