Thermostat sits under upper hose inlet to engine as one would expect, yes. Remove the housing (aka "Water inlet fitting) (3 screws), and you will find the thermostat underneath.
Forgive me for it appears I mis-interpreted your previous post.. been long boring day today.. I read it a bit fast, and as they say,,, Reading Is Fundamental... I owe you one somewhere??? We talking the 3.3? "Water inlet fitting" (see item 5 in pic) is even Hyundai's lingo for it.