some tips on installation
Some additional tips for anyone else looking to install the armrest themselves:
I ordered the armrest on eBay for $170 (shipping included) and decided to install myself (dealerships quoted me $140-$160 for installation).
I primarily used the pdf directions downloaded from http colon slash slash scionpartspeople.scionofpuyallup.com/product/iA/2016/Comfort%20and%20Convenience/Center%20Armrest.
Once you get to the part where you're going to screw the bracket in, you'll find that the holes you've cut out (by removing the tabs) in the inner console aren't larger enough to even get the back legs in. Bundu solved this by disassembling the bracket, sticking the legs thru the bottom of the console and reassembling the bracket. I didn't have the right size allen wrench and thus couldn't take it apart. The pdf instructions tell you to enlarge the holes by scoring the plastic to the outer wall and pushing down, exposing the hex nuts. I found this impossible to do with a boxcutter. Instead I used a drill and a spade bit to weaken and poke holes in the plastic, then I chipped away at it with a screwdriver and boxcutter (so elegant). Then I put the bracket in and it fit thru the holes, but I couldn't get it over both screws at the base. So then I realized that I was going to have to chip away plastic toward the inside of the inner console (enlarge it the opposite way). This is what I ended up with: http colon slash slash i.imgur.com/jMGVzaN.jpg. Finally, the bracket's back legs fit thru the holes and over the screws.
Another thing to add: the spare plastic Bundu mentioned may have been the "inner shield and outer bushing" that go in the "upper adapter" part. The outer bushing doesn't fit well inside of the inner shield, so I taped it in place. Following the pdf, I also taped the inner shield to the adapter before adding the armrest and carriage bolt. I installed it the pdf's way and Bundu's way (without the inner shield and outer bushing) and I think it closed more smoothly and firmly with the inner shield and bushing.
I also agree with Bundu about maybe using bolts instead of the hex screws (the back ones) when affixing the upper adapter to the lower base. Again I didn't have the right allen wrench for these and I couldn't get them as tight as I would have liked and I think the upper adapter lifts a little when I use the armrest because I didn't get this that tight.
Just did this last night. I might report back in a bit with my experiences of the armrest. I'm not handy at all and know next to nothing about tools, so this took me about 5 hours (you may not have to watch youtube videos to figure out how torque wrenches work). Ask away if you want to know anything else or want advice on your own installation.