Their stylish departure was captured in a short video posted to Twitter by Kensington Palace Saturday afternoon, and several eagle-eyed Twitter users noticed something somewhat surprising.
The Duke and Duchess of Sussex depart Windsor Castle for a reception hosted by The Prince of Wales at Frogmore House, in a silver blue Jaguar E-Type Concept Zero. This vehicle was originally manufactured in 1968, and has since been converted to electric power #RoyalWeddingpic.twitter.com/hRrxEUlFlJ
After Harry opened to door to the vintage Jaguar and Meghan sat down in the passenger seat, Harry walked around to the driver's side of the car, as the 36-year-old Duchess reached over and opened the door for him.
"It appears Meghan Markle passes Sonny's door test from A Bronx Tale...as Harry walks around back, she reaches over to unlock his door," one Twitter posted.
It appears Meghan Markle passes Sonny's door test from "A Bronx Tale"...as Harry walks around back, she reaches over to unlock his door. https://t.co/UmgImVRCli
The remark is in reference to a scene from the classic drama, set in 1960s New York, in which Sonny -- played by Chazz Palminteri -- gives some dating advice to the teenage main character, Calogero -- played by Lillo Brancato, Jr.
As Sonny explains it, the door test consists of pulling up next to the person you're about to go on a date with, and locking both doors. You get out of the car, walk over to them, bring them to the car and unlock the door with your key, so they can get in.
As you walk around the back of the car, you look through the rear window to see what they do next.
"If she doesn't reach over and lift up that button so that you can get in, that means she's a selfish broad, and all you're seeing is the tip of the iceberg," Sonny says.
Clearly, the Duchess of Sussex is anything but selfish, as proven by her years of humanitarian work as a global ambassador for World Vision Canada and efforts to raise awareness and support for providing clean drinking water to places like Rwanda. But also, the door test.