Paul Cummings, who liked to entertain customers while working at a dealership, recalls kidding around with an older couple as he touted the interior quietness of a car on the lot.

He put them in the vehicle, closed the door and then, with much animation, pretended he was yelling at them.

“I really was just mouthing the words,” says Cummings, who now heads a sales training firm. “Then I opened the door and said, ‘See how this car blocks out noise; I bet you couldn’t even hear me.’”

They got the joke and Cummings got the sale. “You want people to say ‘wow’ not ‘whoa,’” he says of his clowning around.

It’s obviously not for everyone.

A Rolls-Royce dealer might put a quivering hand over his mouth at the sight of a salesperson doing a Jerry Lewis routine before urbane customers who call Fifth Avenue home.

But a little playfulness works if you read customers right and perceive they’d be open to it, Cummings says.

I thought about that while talking to James Saker after his presentation at an E.N.G. automotive conference in California.

He is a professor at Loughborough University, a U.K. business school with a degree program for students pursuing professional careers at dealerships.

People approaching their jobs with a sense of “playfulness” perform better and learn quicker, Saker says.

“They see the whole thing like a game, like playing a video game, where you experiment and take some risks,” he says.

That said, he adds a caveat: Don’t have too much fun.

“If you take your job too lightheartedly, you run the risk of being frivolous,” he says. “You don’t want people to think you aren’t taking them seriously.”

But his research shows that a playful approach can go a long way.

“It’s a major trait of successful car people,” Saker says. “It allows them to learn about customers better; to bounce back; to figure out a computer program; to display a ‘let’s-do-it mentality’; and to enjoy work because it doesn’t seem like ‘work.’”

As director of Loughborough’s automotive-management center, Saker oversees various studies on what works and doesn’t work at dealerships.

He and his research team look at everything from employee behavior (and misbehavior) to dubious showroom decorations intended to enhance sales.

He tells of how a well-intended British dealership, at the urging of an ad agency, positioned giant plastic stand-up numbers – 1, 2 and 3 – on the sales floor.

They were supposed to stand for 1. Choose, 2. Try, 3. Buy. But that was lost on most customers as they tried to maneuver around the bulky numbers to get a closer look at the showroom cars.

“In reality, the numbers just got in the way,” Saker says. “And kids were swinging on the ‘3’ so it became a safety issue, as well.”

Today, because of Saker’s findings, the number of numbers on that dealership’s sales floor is zero.

Saker says it’s easier to cart off gimmicky showroom fixtures than to change inappropriate human behavior. His researchers come across plenty of that at dealerships.

For instance, although a test drive is considered vital to the car-selling process, slacker staffers at a Belgium dealership couldn’t be bothered.

“Their customers were actually asking for test drives and were refused by some sales people who considered it as too-hard work,” Saker says.

Then there were the insensitive Spanish dealership employees, evidently fans of slap-stick comedy. What did they do when a customer accidentally bumped face-first into a plate-glass window?

“They laughed,” Saker says, shaking his head.

It’s one thing to try to make customers laugh, as Cummings did as a car salesman.

But for Professor Saker, laughing at customers gets a failing grade.