LONDON — When actor Neal Foster stepped onto the makeshift stage on a dreary December day, he gazed out at his audience: tucked into hundreds of parked cars, trucks and SUVs.

“It’s a peculiar experience, but it’s really working well,” said Foster, who is performing in a touring outdoor Christmas show put on by “Car Park Panto.”

Pantomime theater — panto for short — is one of Britain’s great festive traditions, up there with mince pies and the queen’s speech.

The shows are often loosely based around fairy tales, such as “Cinderella” or “Sleeping Beauty,” with songs and snappy repartee. But there’s also slapstick, cross-dressing, outrageous costumes, some bawdy humor and audience participation.

Think Vaudeville but sillier. Or Disney but with an ample dose of “Monty Python.”

The shows are wildly popular — and lucrative, especially for theaters outside London, where the money made from pantos can help fund productions for the rest of the year.

If a family goes to one theater show a year, it’s usually a Christmastime panto. Children, parents and grandparents pile into theaters, and cheer and boo and shout things like “He’s behind you!” to warn the hero that a villain is close.

The pandemic has had a devastating impact on British theaters, with many remaining dark. But when the government lifted restrictions earlier this month, a few reopened with strict social distancing rules.

Prince William and Catherine, Duchess of Cambridge, recently took their three children to see “Pantoland,” a panto mash-up of skits from previous productions, staged at Andrew Lloyd Webber’s London Palladium theater. The royals even narrated a video about the gala event. Five days later, the show was closed as rising coronavirus cases led to a wave of new restrictions in London.

Alistair Smith, editor of the Stage, a trade publication, said the sudden cancellations “have had a damaging impact on the box office and a damaging psychological impact for those who thought they were finally going to work and now had that snatched away at the last minute.”

Government officials have warned that tougher restrictions in various parts of the country can’t be ruled out, as the health system is under strain.

So Britain’s Christmas panto season is canceled? Hardly. In true 2020 style, panto found a way to navigate the pandemic.

A few venues in areas under looser restrictions are staging shows. Many more are live-streaming Christmas or panto shows online, including venerable venues like the National Theatre and Old Vic.

Then there are those getting their theater fix in parking lots.

“It was absolutely brilliant,” said Paul Smith, 39, who recently watched a live show from the comfort of his Ford C-Max parked in an airfield near Duxford, about 60 miles north of London. “As a family, we’ve done pantomime pretty much every year since the kids came along. We think it’s an important English tradition.”

“It was great,” he added, “to do something that seemed a little normal.”

Not too normal, though.

“There wasn’t the traditional boos and hissing and cries of ‘He’s behind you,’ but they did work out ways to do it with beeping horns and flashing lights and windscreen wipers, so it worked out,” he said.

His family listened to the live performance over FM radio. They could make out the actors on the stage, about 200 yards away, but mostly watched the cinema-size viewing screen.

The tour was the brainchild of Guy Robinson, who created “Car Park Panto” and teamed up with the Birmingham Stage Company to stage “Horrible Christmas,” a story about a boy who goes back in time and tries to save Christmas.

Their show is touring 17 sites across the country, many of them near airports, sports stadiums and racecourses to accommodate the drive-in audience. Organizers have sold 17,000 tickets.

Robinson said he put on a number of drive-in shows over the summer and found there was an appetite for outdoor entertainment. He then decided to put on a panto tour.

“The U.K. has never been a massive area for drive-ins. There isn’t the California dream of your roof down watching a movie. There’s too much inclement weather,” Robinson said. “But this puts you in a safe bubble, and people are grateful just to do something.”

He said there’s still a nervousness that on any day, at any hour, their next show could be canceled. They recently called off shows in Cardiff, Wales, and Edinburgh, Scotland, because of pandemic restrictions and another in the English city Exeter due to “torrential rain and strong winds.”

Robinson said Saturday he was waiting for official guidance on what impact, if any, new restrictions announced by Prime Minister Boris Johnson will have on remaining shows.

Organizers also have isolated the cast and crew in social bubbles until the end of the run Jan. 4. The cast is living on a tour bus and being tested for the coronavirus weekly.

“It’s like nothing else I’ve ever done,” said Foster, an actor who is also manager of the Birmingham Stage Company. “The first time I walked onstage, I just started laughing. I hadn’t performed to 300 cars before, but I got used to it.”

Perhaps the biggest change was adjusting to the sound of car horns.

During rehearsals, Foster got someone to say “beep, beep, beep” in the background as a way to prepare the actors for the wall of noise that would hit them when onstage.

“Normally, when an audience boos or laughs or claps, you wait for them, wait for it to die down. You play an audience. It’s like sort of riding a wave,” he said. “But you can’t do that in a car park with 300 cars giving it.”