I designed this in TinkerCAD because I like to keep a small bottle of hand sanitizer in my Tesla Model 3 cupholder, but got annoyed that it was preventing me from using both cupholders. Usually the hand sanitizer bottle would tip over preventing me from using both cupholders, or, best case, it would take up one of the cupholders.
With this printable insert, I'm now able to store the hand sanitizer in the little bridge between the two cupholders, while still being able to safely hold two cups. The circular parts also have a small ridge designed in, so very light spills will be contained within this insert and will not sully the actual cupholders. This insert is easy to remove and clean by simply gripping the pieces in the center that hold the hand sanitizer bottle and lifting it out.
In my photos the insert is printed using a light gray PLA for easy visibility, but I recommend printing this with black PETG, or other high temperature material. I used this gray one for a while and it warped badly in the sun and always looked weird. Black is much better.
I found that the walls that hold onto the hand sanitizer bottle are weak along the layer lines, so printing this standing on its wide edge with or without supports gave me a much stronger result.
The author hasn't provided the model origin yet.