About this 3D model
Inspired by Jagahati's model here . I wanted a similar one that would fit a Hydroflask 32oz with a silicone boot. So I remade it and enlarged the opening to 96.5mm wide. (3.8 inches) Should fit most cupholders. (Boot + bottle is 94mm - Normal bottle is ~ 91.5mm) Highly recommend printing with the following settings: 4+ Perimeters. 50%+ Infill .28 Layer Height .5 Line Width All of these will add to the strength of the print.