A link for you:
When I could not find a plug-and-play for our Element, I considered making my own, using diodes and Honda connectors. Sometimes the connectors and pins are available and not that expensive.
If you find that doesn't work for your Kia, you can buy a diode-based "tow vehicle" harness
AND a trailer tow harness
. Strip the connectors (with their wires) off the trailer harness and butt-splice them into the "tow vehicle" harness.
Of course, if you're comfortable doing that, you may as well build your own harness, because there's nothing magic about (almost all of) the pre-made "tow vehicle" harnesses. (I say "almost all of" because a few of them contain electronic circuits that provide functions in addition to just that of the diodes).
Anyway, read Scott's post (the link I provided at the top), and then you'll have some ideas.