wind noise, back of cab

I have a 2014 access cab with a leer shell that is cab high. I thought the wind noise was excessive prior to the shell being added, but it is terrible now if there is any cross wind. I had the truck in the dealer today for regular service and asked them to test drive it and assess the wind noise. They said the noise is originating from the space between the shell and cab. The technician said there is an after market wind deflector that addresses this. I have seen the side window defelctors but nothing to interupt the negative pressure generated between cab and shell. Has anyone seen such a product or have a fix?
Thanks

 

I have a 2014 that produces a wind sound at random times when I'm going above 60mph. Sound like its coming from the passenger door or passenger side mirror

 

I read about someone taping over the pressure vent back there once, might be worth a shot.