George Arison grew up in a place full of constraints.

In his childhood in the 1980s, in a country that became Georgia after the Iron Curtain fell, there was no free press and little Western media. (Though he knew college students there were revolting against the Soviet Union's suppressions.) But he knew all along that he shouldn't just accept the limitations that so many others simply did. His father, a geophysicist, taught him this much.

"My dad from the time I was a very little kid, would have these crazy ideas, like, 'you are going to study in the United States,'" says Arison. "But he thought it was possible. He always pushed me to do things that seemed impossible." 

So little George dreamed of America. He started learning English when he was two, and later he he studied it more intently by watching the only bootlegged American TV channel he could get: CSPAN. Which is why, when he was 12, he says, he memorized the full name of every member of Congress.

By the time he was 14, in 1992, the Soviet Union had dissolved, and Arison's dream of studying in the United States was coming true. After applying via fax and unreliable mail service, he'd gotten accepted by a boarding school in Maine. He went on to a good American college, too--Middlebury, in Vermont--and to jobs in Washington, D.C., first on Capitol Hill and then as a consultant with Boston Consulting Group. He also went back to his native Georgia, where he worked on a political campaign and went on to write a book about his country's transition to democracy. 

But that feeling that the impossible wasn't really impossible--that thing his father had taught him--kept nagging.

"Starting a company in a sense is an impossible thing to do. You are saying, I can do something that no one else has been able to do," Arison told me during a recent visit to New York City. "Sure, you have to be sort of arrogant to do that. That's a trait that all good entrepreneurs share."

In 2007, he co-founded Taxi Magic, a taxi-hailing system that competed with the likes of Uber, Lyft, and Hailo. (Today it's called Curb, and was sold to VeriFone in October.) It grew steadily, but within years Arison was disagreeing with his cofounders over whether to focus marketing the product to businesses or to consumers--and whether to work with cab companies or their independent drivers only. At the same time, Arison, who had significant equity in the company, needed his green card renewed. "Because of the equity, they didn't consider Taxi Magic a 'real job' for me," he says. Feeling uncertain about the company and his own future should he stay, he left and took a project manager job at Google.

He loved working at Google, he said, but it wasn't long before his vision of the American dream took hold again and he got the itch again. 

"What coming to America showed is that you can dream something impossible and make it happen," he says. "Because I grew up in a very constrained environment and you couldn't do what you wanted, now I get really enamored by this idea that you can do what you want at any time."

He teamed up with Minnie Ingersoll, whom he met at Google--she led the development of Google Fiber--and by 2013 they had a new startup idea. They would call it Shift, and they sought nothing less than to transform used car sales, by managing every step of the process for individuals who want to sell a vehicle. They also wanted to make buying a car easier; if a customer wants to see a car from Shift's online listings, a Shift staffer brings it to her straightaway. (Also on their founding team was Christian Ohler, an engineer who worked on Google Wave and Dropbox's APIs, Morgan Knutson, also a Dropbox veteran, and Joel Washington, who, like Arison, previously worked at the Boston Consulting Group.)

Shift has plenty of competition. There's used car marketplace Beepi, which is headquartered in Los Altos, California, and which has $79 million million in investment from Sherpa Ventures and others. In New York City, there's Vroom, which has raised $108 million in debt and equity. To do battle, and expand beyond Los Angeles and San Francisco, its current markets, to 20 cities--which it hopes to do in 2016--Shift is armed with nearly $75 million in venture-capital investment from the heavyweight likes of Goldman Sachs Investment Partners, DFJ, and Highland Capital Partners, among others. Since June 2015, Shift's sales have increased fiftyfold.

What sets Shift apart from its competition--and from the old used-car dealership--is the level of service it offers to sellers and buyers. While both Beepi and Vroom purchase and re-sell vehicles (usually by shipping them to the customer), Shift keeps everything local, working with buyers and sellers in the same metro area, so that they can offer on-demand ("instant," in Shift's parlance) test-drives of vehicles. A member of Shift's team of "Car Enthusiasts" drives a vehicle out for each request. They also are on hand to come to a potential seller and assess a vehicle, help set a price and facilitate any necessary repairs, and photograph the vehicle.

"It's a huge market that we see the ability to rethink and rebuild," Emily Melton, a partner at venture-capital firm Draper Fisher Jurvetson, which co-led the company's Series A round, told the Wall Street Journal.

With Shift, Arison is hoping not just to transform used car sales into a seamless, pleasant, more profitable experience for the seller. He's also hoping to change the status quo for used-car loans (currently, most banks that offer them pay auto dealers a significant fee to vouch for the ownership and upkeep of the car, and plenty don't offer auto loans without such). So add "become a financial-services company" to the lists of Shift's big, hairy, audacious goals for 2016. It also wants to become your mechanic: Arison says that before long, anyone who's purchased a car through Shift, can get a Shift mechanic to come straight to them to do oil changes or minor repairs. Shift is indeed aiming to become what the press often calls it: "Uber for used cars."

When I ask Arison to gaze into the more distant future, five or even 10 years down the road, he barely pauses. "I ultimately hope someday Shift becomes a platform for people to build something on. Maybe an enthusiast in Des Moines can set up a business using our platform," he says.

"I'm not totally sure what it will look like," he told me. "But I do know America has been that platform for me, and I want to build that platform for everyone else."