This Long Island home takes a garage sale to a whole new level.

In Mattituck, a residence recently began showings at full throttle as it unveiled 41 classic cars and motorcycles the homeowner is including in the $3.5 million purchase price, The Post has learned.

The three-bedroom dwelling and the cars are part of a 1.6-acre estate on Sound Avenue. It’s all coming to market as the owner ratchets down her holdings in the area.

The package of vehicles — ranging in age from a 1947 Chrysler Town and Country with wood paneling, to a 2004 twin turbo-charged Porsche 911 — are part of a vast collection that also features vintage Bentleys, Cadillacs, MGs, Corvettes and even a Studebaker.

The vehicles are all in working order and fill a cavernous climate-controlled garage that includes a lift, a detailing area and auto memorabilia as far as the eye can see.

The total value of cars and motorcycles is not being publicly released, said listing agent Sheri Winter Parker of Corcoran. But an online look at sales of the same models and their comparable mileage shows that some are worth upwards of $100,000.

While that sounds like a gearhead’s dream, the house itself has unique touches and may be the only one of its style on Long Island. It’s a luxury “barndominium,” a design featuring expansive modern country-style open floor plans, 30-foot-high ceilings, skylights and hardwood floors. The goal is to create affluent rural living through a blend of rustic appeal with high-end features that provide comfort as well as functionality.

The property itself is part of a coastal community that contains a mix of high-end houses and more modest abodes, and was purposely designed to be as unobtrusive as possible, owner Gail Dessimoz said.

“We were very careful to build something that blended with the area and was not a monstrosity,” said Dessimoz.

Still, once on the site, it’s apparent something big is going on.

“It’s the cars,” Dessimoz said. “They are the calling cards.”

Prospective buyers will not have it easy, though. Traversing the garage will require flexibility to squeeze through narrow rows without catching coats on the wings of a 1957 Cadillac El Dorado or bumping into the elongated front of a 1965 Buick Riviera, among other pronounced features that cars of yesteryear flaunted.

Dessimoz and her late husband, Michael Fields Racz, built the car/home complex in 1998. They bought the site two years earlier for $55,000, property records show.

The home has been associated with seasonal rentals, most notably $80,000 stays from Memorial Day through Labor Day. It is not currently occupied.

Dessimoz and Racz ran a New York City advertising agency that targeted enthusiasts, like sports car afficionados and high-end electronics collectors.

And while their cars were a high-profile family passion, the couple’s most indelible accomplishment may be the iconic catchphrases they introduced over the tristate airways.

The TV spots they created for the Broadway show “Gemini” culled iconic lines like, “I’m not hungry, I’ll just pick,” said to Danny Aiello by his wife as she dives into a plate of spaghetti, and the admonition, “Take human bites!” from a mother to her chowing-down son.