Your automatic/electric car, the ball park, the movie theater… you name it. Anywhere you have a cupholder, you can now have a gear shifter. Fix the 2 shaft halves together and put in the cup, pin the TPU gate and top gate to the cup, add the shifter to the shaft and shift away!

I made 8 knobs to fit up top, plain, the shift pattern, the classic 8 ball, the Bambu logo, a single benchy version, a two color benchy version, a negative benchy version that will fit a standard benchy on top (I'm sure you've got a few to spare), and my favorite: the fidget-able rotary. One plate has all the shifters and half use two colors, so be aware of that before you try to print all 8 at once. Also note the dorito is on the plate with the silver parts, not the shifters. OD of the shaft is 8mm if you want to make your own knob, or just start with my plain one.

I opted to make the shaft 2 piece rather than a tall narrow print susceptible to tiny amounts of friction from the new material pulling it ever so slightly off kilter towards the top of the print preventing the knob from fitting. There's a square peg to help align at the base + some alignment holes for filament. Glue helps too.

The TPU gate has a couple little nubs that require a tiny bit of force to push through which give a satisfying shift and help retain the shaft at any of the six positions. There's also an extra ring part to use if you find the cup too small for your holder to help fill the space and prevent any wobble when shifting.

Aside from one of the back corners, the benchy actually makes a pretty decent feeling shift knob, who would have guessed?