You can save your prized Aston Martin DB6, Porsche 911 or Mustang from the museum of combustion engine history. Or your Fiat 500 and Renault Clio, for that matter.

That’s the message from a growing cohort of European and American startups seeking to carve out roles in the auto transition by converting the roaring dinosaurs of the fossil-fuel age into clean electric vehicles (EVs).

At the high end, companies like Britain’s Lunaz sell a “remanufactured” Aston Martin DB6 for 1 million pounds ($1.3 million), or Dutch firm Voitures Extravert, which sells a reengineered 1960s Porsche 911 for 300,000 euros ($337,000).

At the lower end, startups like France’s Transition-One have developed no-frills kits designed to electrify mass-market models like the Fiat 500 and Renault Clio in a few hours for about 8,000 euros. They are betting they can provide drivers with a cheaper and greener road to zero emissions than scrapping their car and buying a new one.

EV conversion is a cottage industry that’s emerged over the past five years, and been turbo-charged by advances in battery technology and electric motors in the past two. The market is largely untested, and several industry players interviewed by Reuters described an exciting, if precarious, scene.

“It’s pretty revolutionary at the moment,” said Mark Roberts, a 30-year McLaren veteran who is now chief creative officer at British startup Charge Cars. “Almost every month there are new companies popping up and you don’t know who’ll fade away after a year or so or who’ll be there for the duration.”

Next year Charge Cars will launch production of 499 electric versions of 1960s Mustangs, built from the ground up using car bodies produced under license from Ford and starting at 300,000 pounds apiece. The company, which initially set out to convert classic cars, has spent five years developing an electric replica model instead.

“Traditional manufacturers like Porsche can afford to screw up,” says CEO Vadim Shageleev. “We’re a startup, so we can’t.”

Established startups like his have attracted attention from traditional auto suppliers and manufacturers seeking technical input as they transition to electric - Michelin, for instance, has partnered with Charge Cars to test new technologies.

But there may be little room for error as a host of new EV conversion startups strive for scale to help them weather the increasing regulatory standards and costs that have begun to be introduced in countries like France.

“New regulations will wipe out a lot of smaller players because they won’t be in position to meet the standards,” said Chris Hazell, founder of Britain’s Zero EV, another startup working on mass-producing conversion kits for Porsche 964s and other classic models. His company will expand to the United States next year.

There are various proposed routes to scale.

Lunaz, for example, sees classic cars like the Aston Martin DB6 as a good start.

The three-year-old company and its competitors at this end of the EV conversion industry aim to capitalise on the world’s large population of classic vehicles, with an estimated 5 million in the United States alone.

Lunaz typically buys a classic car on the open market or takes a customer’s existing vehicle, strips it down to the bare metal, rebuilds it, gives it a fresh paint job, new interior and an electric drive system and software with a range of about 250 miles.

But Lunaz sees its future in commercial vehicles, and is building a new factory at Silverstone in central England, home to the British Grand Prix, to convert more than 1,000 diesel garbage trucks a year into upgraded electric models.

“Classic cars were the lightning rod to get us to market,” founder David Lorenz said. “But if you want to have a real impact, you’ve got to have scale.”

Lorenz told Reuters the company was scoping out sites for a US plant and one in continental Europe, and was considering going public within a few years.

In France, by comparison, the race is heating up among mass-market converters who spy an opportunity in the country’s anti-road pollution plans, which outpace much of Europe.

All diesels older than 2011 will be banned in large cities from the start of 2025, affecting millions of car owners. Paris wants to go faster and implement the ban from 2024.

New vehicle retrofitting laws introduced in the country last year, which startups say require government testing of about 100,000 euros per generic model to be converted, have intensified the need for scale.

Orleans-based converter Transition-One plans to start selling conversion kits for six models including the popular Fiat 500 and Renault Clio for those diesel owners who cannot afford a new EV. The kits consist of battery, electric motor, power electronics, and new instrument cluster, and typically have a range of about 140 km.

The cost to customers could be close to 5,000 euros including government subsidies, said CEO Aymeric Libeau, who said he aimed to produce kits “at scale” next year, having waited for the retrofitting laws to materialise, with the gear to be installed by independent mechanics certified by Transition-One.

Arnaud Pigounides, CEO of Paris-based REV Mobilities, estimates converting a car to electric cuts emissions 60 percent versus scrapping an old vehicle and producing a new one, in a country home to around 40 million passenger cars.

Pigounides said his company, which offers to convert a range of cars and commercial vans for around half the price of a new vehicle, has orders to convert 370 cars and 1,500 vans.

“The big question is: do we throw all those cars away or do we convert them?” he added.

Chris Pateman-Jones, CEO of British vehicle charging company Connected Kerb, said only “mass market” options in the EV conversion industry could make a real difference to the environment, rather than classic cars.

“The cost of producing a new car is huge, so if you can reuse what’s there it’s a fantastic idea,” he said. “But the challenge is doing it at sufficient scale to actually have a meaningful impact.”

For four-year-old startup Electrogenic, based down the road from Lunaz, the plan to reach significant size is to tap into rural Britain’s four-wheel drive market, specifically the Land Rover Defenders popular among farmers.

Co-founder Steve Drummond said the company was developing a kit for old Land Rover Defenders for 20,000 pounds that local mechanics can install. He added that Britain’s 36,000 farms need four-wheel drive EVs but there are no equivalent new models on the market.

Across the world in California, meanwhile, Zero Labs is aware of the limits of its current business performing electric “restomods” to rebuild classic Ford Broncos and Land Rovers.

The company’s vehicles start at $350,000, but it can only convert around 50 a year - so it is developing electric platforms that licensed auto shops can use to convert classic cars.

“We asked ourselves how do we do 10,000 a year?” CEO Adam Roe said. “Our platforms are going to be our scale product.”