Dylan Shively, 4, of Middletown, Md., explores the James Bond section of the International Spy Museum on Autism Access Day. (Marvin Joseph/The Washington Post)

Katie and Bobby Whalen stood fixated on a gleaming Aston Martin as the rotating license plate clicked into place: “JB 007.”

“Mom, Dad, come on,” shouted Katie, 14, ushering her parents to the gadget-loaded DB5, James Bond’s most famous set of wheels.

“I hope it’s not gonna shoot me,” said Bobby, 17. “Well, it makes some noises so prepare,” replied his mother, Molly Whalen, 49.

Suddenly, two blasters popped out from under the headlights, barrels glowing orange, unloading a hail of fake gunshots before a small crowd.

“It runs through all of its tricks,” said Jackie Eyl, youth education director at the International Spy Museum. “The headlights open up and rifles come out and they shoot . . . but it is a little loud, so we turned it down as much as we could.”

Sebastian Del Toro, 8, of Arlington tests himself to see how long he can hang onto a bar inside the museum’s James Bond section. (Marvin Joseph/The Washington Post)

But “the car is still the car,” she said.

It was the Spy Museum’s first Autism Access Day, as the museum opened its doors Sunday to 450 select guests — people with autism spectrum disorders and sensory-processing differences — and their families. And the museum, brimming with secrets and surprises about the shadowy underworld of spying, embarked on what it called “Mission Possible” to get ready for the big event.

The tweaks included lowering the volume at some exhibits, dimming lights in others and eliminating stimuli that might disturb people on the autism spectrum. Quiet areas were mapped out across multiple floors.

“But it’s still exciting,” said Molly Whalen, whose children have autism and sometimes become reserved in response to crowds, loud noises and other stimuli. “It’s just the sensory-feeling opportunities are so awesome. . . . It allows you to do something like a family.”

Families raved about the lighter-than-usual crowds, welcoming environment and the learning opportunities for their children. Meanwhile, children soaked in the excitement of their surroundings.

[International Spy Museum moving to L’Enfant Plaza in 2018]

“Niiinjaaaas,” bellowed 10-year-old Vaughan Walkosak, rushing over to an exhibit. He had dressed up as a Lego ninja for Halloween.

His mother, Trigie Ealey of Arlington, said the last time Vaughan visited the museum with his father, they called in advance to learn which exhibits they might have to avoid. Now, it seemed, almost nothing was off-limits — including the atomic spies light show they were instructed to bypass last time. In that exhibit, where the museum simulates an atomic explosion with a strobe light, the effect was eliminated so the select crowd could experience it, too.

“He’s just gonna go where he wants to go,” said Ealey, 46. “Wherever he’s comfortable, and see what he wants to see.”

Sunday, Vaughan’s curiosity led him to a display on Minox miniature cameras, “the essential spy camera” for a half-century, according to a museum placard. Vaughan’s vast knowledge of spy gear immediately became evident.

“I really love Minox cameras,” he said. “It can take so many pictures without reloading. If you’re walking around with a regular-sized camera and take 50 pictures, people will get suspicious.”

There was, however, a moment of discomfort as Vaughan felt unsure about riding up the Spy Museum elevator, which features flashing neon-colored light strips. Museum staff members offered an alternate route, but Vaughan decided he could handle it.

Stepping off the elevator, visitors were given the opportunity to go undercover. It was the Spy Museum, after all.

Hollie Robinson’s son, Riley, chose Billy Henderson, 14, as his alias.

“I really like eavesdropping,” the 10-year-old said.

[My son with autism: Oh the places you, too, will go]

For Sunday’s event, families were given pre-visit materials, so they knew what to expect. One packet, called “The social story,” told visitors where to anticipate crowds, bright lights, loud noises and other stimuli. And a “sensory map” noted the quiet areas, hands-on exhibits and “surprise areas” where there might be environmental stimuli.

Roger Ideishi, director of the occupational therapy program at Temple University, who served as a consultant for the initiative, said the museum wanted to be sensitive to the families. One thing “that’s really important is creating a social environment that is supportive of these families,” he said. “These families often feel scrutinized when they come out in the public. And so they wanna be in a space that they feel safe and supported with the different needs that they have.”

Comfort was the main draw for Karrin Lukacs, 47, husband Michael, 42, and their 12-year-old son, also named Michael.

When they’re out in public, she said, they will sometimes feel uncomfortable because of how people react when their son makes noises in response to stimuli. For example, they became uneasy on a family trip to Universal Orlando, where they saw the Blue Man Group.

“People were shooting us looks,” she said. She thought, “Oh, my God, should we leave?”

But not at Sunday’s screening of the Spy Museum’s introductory film, even as son Michael reacted out loud.

[Want to know what it’s really like to have a child with autism?]

“Not one person turned to give us a dirty look,” Karrin Lukacs said. “There’s no judgment.”

“It’s a safe space, all understanding folks here,” said Joshua Taylor, a training associate for Virginia Commonwealth University’s Autism Center for Excellence who served as a consultant for the event.

Funding from Northwest Federal Credit Union supported Sunday’s complimentary access day, organizers said. The museum hopes to make it a twice-a-year and, eventually, quarterly offering.

As the walk-throughs wound down and visitors had passed the Aston Martin and the ninja exhibit and seen the atomic reaction, they were surprised to find even more to take in.

“What spy museum is complete without James Bond?” Sasha Dayringer, 28, said to no one in particular as she stepped into the first-floor Bond exhibit with her brother Christopher. Did he like spies, she was asked.

“I’m not sure,” she said, as the 12-year-old slinked around a corner, keenly exploring the spy gear. “It’s his first time.”