You ever leave anything behind in a taxi?

I swear the cab companies must install ‘stuff magnets’ under the back seat to suck your personal effects right out of your pockets.

I don’t take cabs any more than I have to, but I’ve still left behind enough loot to outfit a Salvation Army thrift outlet. You name it — books, magazines, ball point pens, groceries, a harmonica or two and once, a bag of dirty laundry.

Naturally, I never saw any of it again (and I’m not holding my breath on the dirty laundry — although possibly the cab driver is).

I’m unusually gifted when it comes to leaving my property behind in taxis, but I’m not as good as Philippe Quint.

Mister Quint is a New York musician, and a very talented one, to boot.

Talented enough to give a one-man concert in Dallas, Texas last spring.

On his return to Manhattan he flagged a cab at the airport, took it to his apartment, paid the cabbie and retrieved his overnight bag from the trunk.

As the taxi pulled away and Mister Quint fumbled with his front door keys, something was gnawing at him. He felt … lacking. Unfulfilled. As if he’d forgotten something.

Indeed he had. In his haste, Mister Quint had left his violin in the backseat of the taxi.

Actually it wasn’t his violin. It belonged to two benefactors who had loaned it to Mister Quint for his concert.

And the violin he’d left in the taxi wasn’t a Japanese knock-off. It was one of only 700 or so hand-crafted by an Italian gentleman some three centuries ago.

The violin Mister Quinte had left in the taxi was a Stradivarius.

The violin Mister Quinte had left in the taxi was worth $4 million.

Four. Million. Dollars.

Mister Quinte did the only thing a person can do when they have inadvertently left an object worth $4,000,000 in the back of a taxi which has disappeared and they can’t even remember which bloody taxi company it was. He sat down on the sidewalk and cried.

And then he sprang into action. Yellow Cab! He remembered that it was a Yellow Cab from Newark that he’d been in.

He phoned the head office. Naw, no fiddle’s been turned in here, pal. Hours went by. Philippe Quinte considered changing his name, moving to Tanganyika, jumping out the window…

Then his phone rang. It was the Newark police. The driver of the taxi Mister Quinte was in — one Mohammed Khalil — had turned in the violin at the end of his shift. It was at the taxi stand right now. Did he want to come down and pick it up?

After he got the violin back, Mister Quinte tracked down Mister Khalil.

He thanked him, he embraced him, he pressed a $100 tip on him. Mister Khalil waved it all off. “Anyone would have done the same thing,” he told a New York Times reporter.

Well, maybe for a cellphone or something … but a $4 million dollar violin?

“Everything we find is valuable to someone,” said Mister Khalil. “If you lost your pen, you would think it was valuable.”

Philippe Quinte was feeling unfulfilled again. How could he show his gratitude?

Then it came to him — he would give a concert. Not at Carnegie Hall or the Lincoln Center, where Philippe Quinte usually gave his concerts —at the Newark International Airport under a vinyl canopy covering in the parking lot by the taxicab holding area.

And he did.

Quinte played the theme from the movie The Red Violin. He played Gershwin’s It Ain’t Necessarily So. He played a Paganini Variation and the Meditation from Massenet’s opera ‘Thais.’

The audience — some 50 cab drivers including Mohammed Khalil — loved it.

They clapped and they danced. One of the drivers, a recent immigrant from Ghana, shimmied and moonwalked across the gravel to the music.

“I like that he came here,” the Ghanaian said, “And, yeah, the music, I like it.”

So did the man responsible for reuniting Philippe Quinte with Signor Stradivarius’ creation.

Mohammed Khalil sat front row, center, resplendent in his best black suit, with pink shirt and matching tie.

The day was a double celebration for Mohammed Khalil. Not only was he being honoured for his honesty, he was retiring. It was his last day of work.

Talk about going out on a high note.