Got them finished, and they're pretty good, if I may say so myself. The tops of the bracket arms have kind of a rough texture. I somehow managed to accidentally print them without supports, and that's how they came out. I don't want to sand them, because I don't want to make them thinner and weaken them. I think I'm going to either print cap pieces to cover them or use a bit of bondo, sanded and painted. I'll try the printed cover pieces first.
The bracket doesn't need anything to help hold it in place between the dash parts. It wedges in there securely as is.
They're a little bigger than a normal 12oz can.
I've only tested them with a few different size cups. I know they won't fit the big cups from Sonic. The smaller bottom part of those cups fits in, but the larger part prevents them going far enough down into the holder to be secure. I don't drive around with those things much anyway. Only if I'm just transporting them home. Medium sized styrofoam cups fit, but are tight (Sonic cup on the right). They fit a medium paper cup perfectly (Subway cup on the left).
When they're not in use, they fit easily in the armrest.
