This would make the Bluth family proud.

A grinning La Guardia Airport worker took a lunchtime joyride in an “Arrested Development”-style stair car — even though the wacky contraption isn’t allowed on city streets.

The driver, a regular at a nearby pizza joint, was spotted cruising in the Southwest Airlines vehicle on 19th Avenue and Hazen Street at 12:30 pm on Saturday.

But just because Michael Bluth rolls in a staircase-on-wheels, doesn’t mean normal people can.

“It is not legal to drive on a public street,” a DMV spokeswoman said.

The vehicle displays a Port Authority license plate marked “A 3537” — which permits driving only on airport premises.

“This is not acceptable behavior,” Steve Coleman, a Port Authority spokesman. “We will immediately begin to identify the offending vehicle and driver and will take appropriate action.”

Southwest spokesman Chris Mainz apparently disagreed, saying, “Nothing unusual or out of protocol on this one.”

Jason Bateman, who plays Michael Bluth in the hit show, saw no humor in the life imitating art.

“I get what you’re trying to do. But you know I can’t comment,” he told The Post. “And please don’t call me. Do you understand? You have to go through a publicist. It’s totally unprofessional.”

Additional reporting by Brianna Farulla