The roof line would have generated a lot of lift, so I suspect the wing helps (be high enough speeds). Aerodynamically it should be pretty efficient since the underside of the wing is unobstructed, but the OG wings were metal, so you were mostly just carrying around a weight penalty on your trunk.
The way the top slopes down on fastback cars draws air down with it, and creates a low pressure zone above the trunk, which results in a lifting force over the back wheels.
Edit: here’s a good 12 minute overview of common care shapes and aerodynamic drag and lift in 12 minutes.
The roof line would have generated a lot of lift, so I suspect the wing helps (be high enough speeds). Aerodynamically it should be pretty efficient since the underside of the wing is unobstructed, but the OG wings were metal, so you were mostly just carrying around a weight penalty on your trunk.
Why does the roof line generate lift?
The way the top slopes down on fastback cars draws air down with it, and creates a low pressure zone above the trunk, which results in a lifting force over the back wheels.
Edit: here’s a good 12 minute overview of common care shapes and aerodynamic drag and lift in 12 minutes.
https://youtu.be/n7EYKVEL7Ds