Well Dont I feel Like An Idiot

For the past couple of months since summer arrived I have been chasing a car that want's to run with the electric cooling fans on the highway. It never overheated but it worried me. at the same time the water pump stared weeping so I thought the small pressure loss may be the problem. So I changed it and seeing as the coolant was lost anyway I changed the thermostat as well. No change, still wanted to turn the fans on. I had a look at the radiator and it was looking a bit worse for ware so I thought I would change it, but an encounter with local wildlife meant that the whole radiator, air-con condenser and fan needed to be changed. So I got the car back with most of the front replaced and it is still doing it. I went to the dealer to ask then to see if they know what was going on. The guy had a look and told me that 3 of the 4 air ducts that channel air through the radiator are missing. I had forgot the basic rule, no air = no cooling. At low speed that fans are on to keep the airflow up through the system, so I didn't think anything of it. Don't I feel like an idiot.