We just picked up our new Sorento EX V6 AWD and drove it home over 800 miles on interstate highways from Ogden Utah to Eugene Oregon, where we live.
At freeway speeds, there was a constant, annoying rattling sound from the right front. It was not sensitive to road conditions (i.e., bumps or rough surfaces). It seemed to be coming from outside the cabin.
Nothing appeared loose in the engine compartment.
However, there is a plastic skirt attached inside the wheel well that I could easily rattle by hitting with my hand. I suspect this is the cause and will take to local dealer to fix.
Here are two photos: