[aerohead]

Originally Posted by JulianEdgar

A well-supported summary. To put it another way:

The use of a template to guide rear extensions, judge the 'purity' of shapes, guide the positioning of rear spoilers on notchbacks, and assess whether a car will have attached or separated flows - they're all just rubbish.

I'm (again) putting it like that because I've noticed that lots of people here can't see the cognitive dissonance of agreeing with two completely contradictory ideas.

At least as a group we now seem to be moving away from invalid 'rules of thumb' to acknowledging that the real-world complexity of car aero modification requires testing, not guessing.

Are we to expect that your second-edition will have your rules-of-thumb edited out?