Bumper to Bumper: 1920

I assume the "D" on 3 of the license plates stands for "Dealer"?
I guess the rakish guy on the left had already purchased his car.

Photo taken in Potomac Park looking back toward the Tidal Basin
with the old 14th Street Bridge in the background?

Metz cars had a unique continuously variable transmission (now called CVT) that became known as Metz Drive. Some of today's new garden tractors employ a version of the Metz Drive system.

in the second car from the left. Mr Sunglasses looks out of place, making sure he's seen above windshield. Rare to see someone wearing them in 1920.

["Sunglasses" as a retail marketing term didn't become common until after the late 1920s, but tinted spectacles, serving the same purpose, have been around much longer. They were common enough in 1920 to be sold at a military PX as shown in this Shorpy photo]

The era was coming to a close but tread on your tires was still a premium feature. Black coloring cost more too but it got popular fast when people realized it made the tires wear longer.

Or it should be, no tread on me (the tires that is). They all can't be bald, can they?

OK listen up, the driver of the second car from the left, DC Plate D-3-995, step out of the vehicle and put your hands up. The charge, driving without a hat.

and obviously is enjoying the ladies in his automobile, on the far left of the screen.

of what parking will be like in the future.