In this image I have drawn a yellow arrow pointing at the right rear taillight area. That RR quarter panel appears to have shadows from the tree above; while the other car (beyond) appears to be in full sunlight. I drew a green arrow pointing at a wheel. And I drew a red arrow pointing at the top of the windshield. The windshield becomes more obvious in another frame where the light refraction bending the edge of the brick column is more visible (already posted earlier in this thread).

Excellent work, Charles!
Note the distinctive horizontal line which is a little above the yellow arrow and is a continuation of "Fedora Man's" crossed forearm in this frame from the Wiegman clip. There's another horizontal line below it which is harder to make out because it's in the shade from an overhanging tree branch.
These two horizontal lines, which are about a foot-and-a-half apart, delineate the light-colored recessed area from the darker color of the main body.
Google "1958 Pontiac Bonneville" to see more examples of this design feature.