[MetroMPG]

I still think your claim of a separation bubble (what you call a delamination bubble) anywhere on the roof of the car is extraordinary.

Invoking Sagan: extraordinary claims require extraordinary evidence.

If your claim (of flow separation anywhere on the roof) were true, it would be a massive mistake on the part of Toyota's aerodynamicists & designers, something I doubt would have gone un-noticed in the wind tunnel.