Millenium GS-3500 B

Yet another one of those things that my bandmates suddenly think has been theirs all along. They are some cheap MFs, because this price for value CANNOT BE BEAT!

At first it seemed a bit flimsy, but that was just mistaken for lightweight. I suppose it would break if you purposefully let it fall unprotected from the back of a van, right on its top end, but this thing is sturdy - a good mix between the right materials and ingenuity.
Just put the guitar neck in the slot and let it go. Go ahead, let it go... Well, you should probably set it up to fit your needs first. Don't go dropping your full-sized electric bass in there after your bandmate has been using it for his electric, shredding, sport-striped guitar.

Probably in some way, this is some combination of borrowed ideas, but it works well! I've tried a few similar solutions. This one seems to have the best of all.
Sure there are other more compact solutions. But do you have a F-Jazz Bass? a Jazzmaster? a Jaguar? a jumbo Dreadnought? Or some other weird-shaped, lopsided, or oversized stringed, strumming thing? This is the answer to your question.