Looking through the replies to kferguson
's post, I think things have changed a little since others were kind enough to reply.
(1) Uhaul will custom make a 2" hitch for the first person to go to their AZ manufacturing facility and leave their car for 3 days. I'm from Rhode Island, and as much as I love driving my Niro, that's too far. After they figure out how to make the first one, they'll mass produce and sell the hitch to the rest of us.
(2) My dealer (in Massachusetts) will install non-KIA brand hitches for the labor cost (about $200).
(3) The Curt 13329 Class 3 Trailer Hitch is compatible with the Niro PHEV, but needs a slight modification. See Bruce's 5/21/18 comment on the amazon.com web page: https://www.amazon.com/Manufacturing.../dp/B0725NM56D
Hope this helps.