Photochop butchery ( aeromodding cars using Photoshop )

[Cd]

Regarding the app I use, it is called ArtFlow.
The 3D app is called Prisma3D.

I'm using both on a Note8.

Caddylackn : Great advice.
This is just a "what if" doodle. I have no real plan to create this.
However, if I did, I would do something similar to what you mentioned.
The windows would raise as far as they could go, and any gaps could be filled in with something custom.
I have a 3d model of the car that is accurate.
It would give me an idea of how far off the windows would be with the roof laid back.

[aerohead]

I finally located a photograph for wind tunnel smoke-flow imaging of the 2020 NISSAN 370-Z ( I'd originally found it online ).
Three smoke filaments are presented.
The second-lowest makes contact with the boundary-layer on the windshield, over the top of the roof, an then separates immediately beyond the roof apex.
The 370 is 1,315mm high, and based upon the 'daylight' between the trailing edge of the upper body, and the local streamline, there's a 82mm separation gap.
A first-approximation solution for reattachment would be a shallow, upswept rear spoiler, with its tearing edge just touching the bottom of that streamline.
Dr. Hermann Burst might have recommended lofting the entire rear contour up to this imaginary line connecting the span.

[Cd]

Looking at the glorious Panhard LM64 car that ran at LeMans in 1964.
Tested in a windtunnel, a large model of the car showed an astounding .12 cD !
Despite having only 78 HP in race trim, the car attained a speed of 137 MPH, all while getting an incredible 37.58 MPG !
This is a Photochop of the car compared to a Mazda Miata.
The cars were even the same color.

[Cd]

Just imagine - even if the aero figures on the LM64 were off by a massive 50%, that car would still have a cD of .18 !

[freebeard]

Bob the tail and cut out the fender flares. Tall, narrow tires.