Your correct Kia does NOT make any flaps for the SX, the rocker mldg's are diff and Kia has not come with a set. Dought they will since the SX has been out for 2 years now. Try a google search for some aftermarket ones.Only for lx and ex. Can't even find them at the dealer.
Here's the trhead, http://www.kia-forums.com/2011-xm-sorento-forum/73898-splash-guards-2012-sx.htmlThere's another thread about mud flaps for SX on this board...keep searching.