I went about this whole project in the TOTAL wrong order, lol. First I found this cup holder trash can lid on Thingiverse and thought it looked great. https://www.thingiverse.com/thing:5948543 I didn't yet have a trash can so I then downloaded what I THOUGHT was the trash can this lid was made to fit. This was my first print ever that required supports and I screwed it up majorly. I wasted a ton of PLA on the supports and they were very difficult to remove. Thankfully I didn't actually waste the time finishing the removal. Then I printed the lid and realized it doesn't fit the can I printed! I probably could have found a can file to fit but as I'm new at this, I had been itching to create my second custom print file so off I went to http://www.tinkercad.com last night and came up with this super simple can. I added a tiny chamfer to the outside corners because there was a similar chamfer to the inside corners of the lid I wanted to use. Just wanted to make sure it was a decent fit. I also added the tiny wedges on the sides (they didn't require supports for me) to give it a friction/interference fit with the lid. I really didn't want to do the FITS mount over again so I took this great model https://www.thingiverse.com/thing:5436067 and cut off the hook so I could stick the FITS mount to my can. It's a perfect fit in the truck's mount point.
The author remixed this model.
I didn't want to re-engineer the FITS mount so I took this awesome hook which looked like a solid design, cut off the actual hook, and used the mount for my trash can. It works perfectly!