I believe on a Dolorean it was the engine lid and there was a flat window right behind the drivers head. I don't remember to well but I think it's like a fiero GT in back, the rear side windows were windows for a nicer side profile and some aero benefits.. I would add the same thing If I did a Fiero GT project.This actually helps the flow of air smooth and it is the "louvered Engine Bay Lid" Whatever is under that louvered Lid is a totally seperate compartment from the passenger compartment. I also believe engine bay heat left through those louvers also.
If you look at this photo, It was actually an aerodynamic mod and sorta funny that you had to open 2 lids to get to the engine which was a POS IMO!
I hope this helped you guys know it isn't to keep the driver cool at all! lol