I think what you are seeing in a photo of the exterior of the 3326 at the car show is where the screen door is stored. My screen door looks just like that...except it is brand new unused and still in the box.
Oh, that would make sense. I thought for a minute you had a genset in your 3326 and I was wondering just how large a unit you put in. All I could think was it would double as bed heater and massaging mattress!