I was amazed at how noisy the top was that I built for my roadster pickup. It doesn't flap up and down, particularly, it seems to flop and flap everywhere. At speeds above 40 MPH you don't hear the radio!!! You do get used to it. I have been told that having the back section of the top open ala the stock originals cuts down on the noise, but I didn't build mine with that capability.