Image copyright Getty Images

Two things have arguably shaped modern Cuba above all others - Fidel Castro and Washington's answer to him... its decades-long trade embargo. When US Secretary of State John Kerry arrives in Cuba on Friday to unveil the new US embassy he will find one effect of the embargo staring him in the face, on the country's roads.

Classic cars are ubiquitous in Cuba.

But while the iconic 1950s Chevrolets, Buicks and Studebakers are a key part of the country's tourist appeal, they are also a glaring and visual expression of the embargo, which first came into force in 1960.

"With these cars, you always need to do something," says Nidialys Acosta of the classic car hire company, Nostalgicar.

"For example, we finished restoring the blue car three years ago," she says, pointing towards a mint-condition turquoise 1955 Chevrolet Bel Air, lovingly named Nadine. "Now we have to paint it again, restore the engine and fix the bodywork. It never ends!"

Nidialys and her husband Julio set up Nostalgicar after Fidel Castro's brother Raul, his successor as president, relaxed the rules on private enterprise in 2008. Passionate mechanic Julio brings the car expertise while Nidialys brings the business acumen.

Of course, original parts for 1955 Chevrolet Bel Airs are hard to come by and Nostalgicar needs to rely on specialist suppliers in Florida or Texas, sometimes travelling to the US in person and carrying the parts back in their luggage, or asking friends and family to serve as mules.

Image caption A Nostalgicar ready to be re-painted

Part of an emerging class of business owners, Nidialys and Julio risked a lot when they took the plunge into the private sector. But three years on, the venture is a success.

Find out more Listen to Will Grant's report Cuba on the Move for Crossing Continents at 11:00 BST on Thursday 13 August on Radio 4, or catch up later on iPlayer. Download the Crossing Continents podcast.

Supporters of the embargo in the US Congress say that over the years, the trade sanctions have forced the Cuban government into relaxing its grip on the economy, thus creating new spaces for entrepreneurs like Nidialys and Julio. Their success, the argument goes, is thanks to the embargo, not in spite of it.

Nidialys, however, would be glad to see the back of it.

"For my business, if Obama ends the embargo that would be the best, because it means more American tourists to rent our cars, more facility to bring in the parts and to maintain and restore more cars. It's for the best."

I leave Nostalgicar to meet a farmer outside Havana. Just 20 minutes' drive beyond the city limits, the countryside becomes thick and fertile.

Doane Silva grows fruit and vegetables: papaya, mangoes, guava, tomatoes and lettuces. Much of it goes to the state but since Raul Castro's reforms he can now sell some of his produce directly to the consumer.

Doane's parents and grandparents worked this land before him but he wants something better for his children.

In the middle of the farmyard is a sturdy Russian tractor, which is missing its starter motor. He shows how to bump start the vast machine.

Asked what he'd want if the embargo was lifted, Doane shrugs.

"It's a long list," he says, before naming crop sprayers, seeds and spare tractor tyres as his most urgent needs.

Doane fears he'd be vulnerable should Washington ever take the controversial step.

Media playback is unsupported on your device Media caption LISTEN: Will Grant considers buying a Cuban car

"Of course, if you look at the size of the land we've got," he says gesturing to the few fields in front of us, "the multi-national companies might come in and start forcing smaller producers like us out."

But it's a risk he's more than prepared to take.

"My children would obviously have a much better life if this embargo didn't exist," he says.

There are other cars on the road which provide physical evidence of Cuba's past: Soviet-made Lada and Moskvitch models from the days when the USSR propped up the Cuban economy.

I pull over by a group of men in Havana tinkering under the bonnet of a Lada. It needs a new carburettor, a part which costs somewhere in the region of a year's wages for the average Cuban worker - $200-220 - so they're trying to fix it themselves.

Image caption Raul, left, and friends working on a Lada's carburettor

One of the mechanics, Raul, speaks excellent English. By coincidence, he turns out to be the son of Ramon Sanchez-Parodi, once Cuba's top diplomat in Washington.

His blue Lada once belonged to his father, who acquired it more than 30 years ago. Like most Cubans, Raul wants to see the embargo gone. But having lived in the US at the height of the Cold War, he is under no illusions that it's going to happen soon.

"It will take a lot of years to come. But I think if the embargo ends, it will be good for Cuba. I don't know how good but it has to be better than living like this," he says.

Still, he also agrees that Cuba might lose something intangible if suddenly every product under the sun was easily and cheaply available.

"Cuba will lose the enchantment that it has. Well, that's the price that we'll have to pay!" he says with a grin.

Isn't that just romanticism? I ask him.

"No, it's real because Cuba is not a common country," says Raul. "You see things here in Cuba that you cannot see any other country. And that's the enchantment. I don't want Cuba to become like Puerto Rico or just another country in the Caribbean."

Image caption Many Cuban cars need to be bump-started - so some are parked on specially made slopes

Image caption Pre-embargo era cars often have often been fitted with Lada engines - this one is an exception

Image caption Is this a Che-vrolet?

Listen to Will Grant's report Cuba on the Move for Crossing Continents at 11:00 BST on Thursday 13 August on Radio 4, or catch up later on iPlayer.

Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.