Many times layers can be counted at the lower edges of the roof. (remonline.com)
A special light sensor located near the top edge of the roof automatically adjusts the brightness of the head - up display to the exterior lighting conditions. (speedsportlife.com)
That party piece, now thinner, works in conjunction with vortex generator strakes on the trailing edge of the roof line, which are sandwiched by two raised «horns». (paultan.org)