I have run with the air dam and basket on and off for periods of time (I live under trees and it is easier to leave them off during the fall season, if I'm not using them, cause they catch falling leaves).

The wind noise is noticeably better to me without the dam and basket.

Graham XC - the quietest vehicle you've ridden in? You have to be kidding. The wind noise is there, with and without the dam. You must have your tunes cranked to 11.