Donald Trump’s fire-engine red, 2007 Ferrari F430 F1 Coupe went on the auction block on Saturday and traded hands for $270,000. That was below the top price of $350,000 it was expected to fetch, but well above the $180,000 or so the car probably cost when it was new.

Reading about the president and his cars always brings a smile to my face because we spent the better part of a spring afternoon in 2005 together driving around Palm Beach in one of his earlier Ferraris. It was fun.

I was staying with Trump at Mar-a-Lago for the weekend, preparing to write his biography, “TrumpNation: The Art of Being the Donald.” On a Saturday morning, I found him standing next to a red Ferrari in the club’s cobbled driveway. He was dressed for golf and holding up his car keys.

“Wanna drive?” he asked me, smiling.

I pondered the thought of flooring it onto Ocean Boulevard and then right out of Palm Beach, with Trump in the passenger seat, but thought better of it. I can barely drive a stick shift and never, before or since, have I driven a Ferrari.

“That’s OK, you drive,” I responded, smiling back.

Trump slid into the car and off we went. He immediately began free-associating about Mar-a-Lago’s history. (Trump bought Marjorie Merriweather Post’s former estate in 1985 with an unrecorded, $8.5 million loan and later had to turn it into a members-only club so he could afford to hang on to it after he ran into financial trouble.)

“Post was said to be the richest woman in the world,” Trump told me as we drove along. “She inherited Post cereals. She then married E.F. Hutton. He quadrupled her money through great investments and everything. Unfortunately, he liked screwing maids. And after the fifth time, she just said, ‘I can’t do this anymore.’ ”

Trump wasn’t finished: “Dina Merrill grew up in Mar-a-Lago in a room designed by Walt Disney, a young Walt Disney, before Walt Disney was big.”

Dina Merrill, an actress, was Post’s daughter, but Disney was working in Los Angeles when Mar-a-Lago was built. He had nothing to do with the mansion. Trump’s Mar-a-Lago staff always grimaced when he told the Disney tale.

When Trump first arrived in Palm Beach — a pristine enclave with its own WASPy social norms — he created a stir. Celebrities showed up as guests and one of them was busted having sex on Mar-a-Lago’s beach. When Trump decided to make the estate a club, Palm Beach residents tried to block the move.

“They went nuts,” he recalled. “The bottom line is that after litigation I ended up winning and I got the right to turn it into a club.” He gunned the Ferrari. “They hated me.”

Trump took a break to play a round of golf, so we resumed our tour later in the day. The Ferrari hummed smoothly, except when Trump couldn’t shift gears properly. The shifters were paddles attached to the steering wheel, and the car lurched or stuttered a bit occasionally as Trump missed cues to change gears. The hands he made famous on the campaign trail years later sure seemed big back then, as he flipped the paddles with his thumbs like a kid playing a video game. But we made progress, cruising along in smoked-glass anonymity until Trump lowered the windows at a stoplight.

An older couple dressed for tennis and driving a light blue Mercedes convertible stared at him, broad smiles spreading across their faces. Trump kept staring straight out the windshield, telling me about local gossip from a few years back that still bothered him.

“I’m the king of Palm Beach. They all come over, they all eat, they all love me, they all kiss my ass. And then they all leave and say, ‘Isn’t he horrible.’ But I’m the king.”

We had dinner later, and then there was dancing by a pool set amid Mar-a-Lago’s floodlit grounds. An armada of body-sized speakers was cranking vintage rock-and-roll and disco music into the purple sky.

At one point, Wild Cherry’s “Play That Funky Music White Boy” blasted from the speakers. Trump, wearing a navy Brioni suit and a baby-blue tie, bit his lower lip and kept his forearms raised near his chest so he could bob and weave in an upper-body-only dance shimmy. He turned to me as the music boomed and leaned in to my ear.

“I bet they can hear this music up and down Palm Beach,” he shouted, adding a few curse words. “And I bet it’s driving them nuts. And you know what? I don’t care.”

That moment of camaraderie eventually passed. Trump sued me for libel about a year later (he lost the case in 2011). But seeing that Trump had put a Ferrari up for auction made me miss driving around with him, just a little.

China’s president, Xi Jinping, is visiting with Trump on Thursday and Friday at Mar-a-Lago. Trump should take him out for a drive.

O’Brien is the executive editor of Bloomberg Gadfly and Bloomberg View. He has been an editor and writer for the New York Times, the Wall Street Journal, HuffPost and Talk magazine. His books include “TrumpNation: The Art of Being The Donald.”