[aerohead]

No matter how much science you throw at some people, it appears to be impossible to move the dial on aerodynamic 'folk knowledge.'
Lift, created at the windshield header can be completely eliminated by the aft-body roofline, if it's streamlined, and reaches far back enough for pressure recovery to act against the top.
By carefully lowering the roof, without separation, the local streamline and boundary layer is exposed to higher ( Bernoulli Theorem ) pressure, as the flow slows along the diverging contour, getting closer to the undisturbed position it originally occupied, before the vehicle came along and displaced it.
This is why the 2013 VW XL1 can ( and has ) safely travelled at 112-mph without any spoiler ( while the original Audi TT was killing people ).