Edit again: There are some things to tweak, like the size of the snap in cylinders and the position of the opening holder, so I made this thing a WIP. Expect some minor changes in the near future.
Customisable box with a cover, which snaps on quite tight. I wanted this to store some USB & phone adaptors in my car, but it may be useful for 100s of other things, so I publish this.
Version 1.1 - wifey had trouble opening the box, so I added an optional gap for putting a coin in. Turn it, and the box opens. I assume her finger nails are softer than mine ;-)
I also added an optional wall, so you can separate things inside. Sizes of opening helper and separating wall had to be adjusted a bit, will print the new version tonight. Removed some minor issues.
V 1.2 - fixed a few things, removed a bug - thanks to molotok3D