a must have for me I have always thought the ADs are classic all on their own. The exterior visor just intensifies the classic look. For me, the visor was the 2nd item I bought - even before i HAD a truck! I picked it up at a swap meet for $100 and had to only buy an additional center bracket on ebay. The visor and the side mount spare tire truely enhance the classic look - but "to each his own" I say, go for it!
As Nate said, there is a speed factor connected with them. I have a couple of Fultons one of which was on my 37 Buick. All was fine with the original 4.44 gear in the rear but after I went to the 2.73's I was so enthused about being able to run in the left (right in UK) lane I overdid it. The Buick just has a rubber channel between the two windshields and no metal strip on the inside like an AD. About 70mph the center of the visor started to lift and the arm clamped onto the stainless trim pulled the rubber divider channel till I could see light. We had to get out the tool kit and remove it to get home. The old Buick needs paint so I'm going to copy the truck idea of having the metal strap from the cab top to the top of the dash. It's sunny here so much of the summer I really like them. I guess speed isn't a factor with yours but watch those gale winds off the North Sea.
I bought one for my 47'. I Like them! I gave it to the paint shop for the grand finale of my 4 year resto project. I picked it up and there was no visor. They said, they couldn't bear to mount it on such a classic. Heck...what do they know...just a bunch of Ford lovers anyway! Flashlight