No just kidding, that last picture was the first mock-up, but it was waaaayyyy too high! It was over 30cm above the roof line.
So I kept working on it and think I’ll end up with a height like this.

Again, the mounts are just scrap pieces for mocking it up.
The real mount will look like this (except wont be made of cardboard – just in case it rains).

And on the car, will look a bit like this

Just need to source some thicker alloy to turn this carboard cut-out into a real wing mount.
Once I have that, I can position it on the car and make the framework that will run from the rear chassis up to the underside of the boot lid to support the aerodynamic loads that this wing will generate – well over 100kg of force when on the Porsche that it came from.
After that’s all done, will need to start working on the front end to make it generate more downforce to match what the rear end will be capable of now.