Back in the day, there were not super mega dealerships with dozens of different optioned trucks sitting around waiting for customers. If the old grain hauler bit the dust and the dealer only had a deluxe, 5-window 6500 in stock would you let the wheat sit for 6 weeks while your special order 3 window came in or would you get the 5 window? I figure that's how a lot of farmers ended up with 5 window.