Did I make a good decision? Brand New Car Issue?

Make sure a Ford technician drives the car on the highway at 60 mph with you to hear that noise. That's the most important thing you need to do. There's no way you should hear any loud noise over the radio with the window closed on a new car in my opinion. It sounds like the transmission's not shifting so that the engine RPMs come down at road speed. Make sure the gear selector is in Drive or Over Drive. You should have read your owner's manual too.