I use Wings 3D (free) to model the aeroform and any unrendered pictures (you can see a grid on the ground and polygons), and Poser 7 (2nd hand) for the renders such as above. The Beetle model was $25 years ago, but there are frees one as well.
One free program that will do it all (with better lighting) is Blender; but boy howdy, does it have a learning curve. Wings has a right-click/fiddle/left-click/repeat work flow that is understandable by me.
There are free models of the Ford Escort available:
Google search
https://www.yobi3d.com/#!/search?q=f...xplorer%252098 They're not labeled but it's the fifth one in the third row, not sure how to download.
Ford 3D Models | 3D CAD Browser Ten different Escorts to choose from, you have to register to download, not sure what the 'box' requirement is
What you might do is take the line of separation at the rear and extrude it back and shrink it to follow the template curve, rather than the half-circular shape of the template itself. Add Dodge Charger sail panels for the Kammback.
Mair was working with torpedoes but the 22° would apply to the top and sides.