Yes, Lexus has a hitch for the '10 but it's a Beast!! (That was the word used by the Lexus parts guy). Costs $550 plus install and takes 2 guy to install. HOWEVER, I found another option. I bought a Curt hitch from TheHitchstore.com --fabulous! It was $170 del'd and the install was pretty easy--excellent help from curtmfg.com. Excellent finish and it all but disappears--unlike the Hidden Hitch brand that I put on my '07RX.
If you plan on hauling a real heavy trailer, then maybe you will have to go with the Lexus beast, but the Curt is quite solid.