I designed this coin holder to fit in my car's cup holder. It's a bit awkward, because the arm rest slides over the cup holder when not in use, and all the other coin holders I've seen are too tall.

The coins sit in the holder at an angle so it's easier to slide them out. Admittedly, this does not hold a ton of coins because it is so short. I was only able to jam 13 quarters in there, but it does the trick if you don't need a bunch of loose change in the car.

I printed this at .15mm with 3 shells. It's held together on the bottom with four screws. The springs, which I CA-glued in the coin pushers, are from McMaster-Carr, item number 9657K414.