This design bends mostly in a single plane, which makes things much easier.
The last 2 bends are at 90 degrees to the main piece, which again is simple.
Despite the simplicity, it still follows the front pillar line and the roof.
The aluminium allows the final shape to be fine tuned in situ.
Notes on bending
here.
Notes on tapping
here.
A template for this is downloadable
here.