Outside air coming in near back window

[Hitec.Redneck]

We have a 2014 3500 4 door with an electric sliding back window (factory) and last night I was riding in the back seat and there was a lot of outside heat coming in near the back corner where the back of the back seat touches the back of the truck. There is no air sounds and you cant feel a draft but you can definitely smell outside air (exhaust and smoke from fires). Anyone ever experience this with their truck?

 

[lpennock]

Check the cab vents on the back wall of the cab between the bed and cab.