I didn't feel like paying $20 for a mirror mounted dispenser on Amazon, so I decided to pay $8 for a bunch of suction cups and build a dispenser around them. That way I'll have a ton left over for more dispensers or other projects. This is 150mm tall, printed standing upright.
This is the exact item I ordered on Amazon:
https://www.amazon.com/gp/product/B071WFNKTB/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1
It fits snugly in the slots on the back. If you end up making this, follow proper suction cup protocol: clean the mirror thoroughly and clean the suction cups thoroughly prior to application. Also make sure to push out any air bubbles.
This will require supports for obvious reasons, but they ripped off very cleanly and easily for me. I didn't make it round because I like angles, but if there's enough desire for it, I could be persuaded to make a round version.
dispenser-round.stl | 80.4KB |