As fsr as I could find out.... They supposedly come with the sockets.... I'm not sure if there is any mod needed.... The part #'s are
33550-T5A-N21 and
33500-T5A-N21....
the downside is that they cost about 300 each....

Thanks for the part numbers! From what I can tell (from afar), those tail light assemblies were offered on the overseas 2017 Honda Fit 'RS'. I found a vendor for them on Ebay (wwwisicarcom, located in Tokyo, Japan). From their detailed photos - it appears it would be a MUCH easier install than the Pandora's box project that I did! Their photos show that the RS sockets for both the Reverse and Turns are 'W21W' (i.e., 7440 / T20), which are the SAME type as on the 2016 Honda Fit! Not sure if the socket ridges would need to be shaved to make them fit, but so much simpler. Appreciate you passing that along! Hope that you find an unexpected $600 in your pants pocket so that you can order a set! :-)

Thank you very much for the detailed instructions.
I've been researching and reviewing the options for amber turn signals on my Fit, after I realized the rear signals weren't amber.
There's been studies that have also concluded that amber is not only more visually appealing, but safer too!
So kudos to you!
https://www.acarplace.com/2018/01/in...%20%3D%20turn.

You're very welcome! I completely agree with you, and feel so much safer with having amber turn signals. They have come in handy when traffic is slowing or coming to a sudden stop on the highway; I activate the yellow flashers as I am slowing down, and traffic behind responds accordingly. Thanks for the article link.

Good luck with your research, and let us know how it turns out (pun intended!)