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It used to be much simpler. Ford made Fords, Renault made Renaults, and Jaguar Land Rover made Jaguars and Land Rovers. You might have known that a Skoda shared a few hidden bits with a Volkswagen, Seat or Audi, but you did not need a corporate family tree and several coloured pens to work out who was in bed with whom.

Not anymore. The latest unlikely pairing is Stellantis and JLR, which have agreed to “explore collaboration synergies across product and technology development in the United States”. The parent company of Jeep – a name that has spent years battling Range Rover and Defender in the SUV world – is now sitting down with JLR to find out where they might be able to help each other.

At this stage, it is an agreement to discuss working together, not a promise that future Jeeps and Land Rovers will share nuts, bolts and batteries. But even the conversation is significant. It tells you plenty about the challenges facing car companies today.

Stellantis appears to be in full friendship mode. It has also announced plans for a joint venture with Chinese car maker Dongfeng to bring its upmarket Voyah electric and plug-in hybrid cars to parts of Europe, potentially building some at Stellantis’s factory in Rennes, France.

That sits alongside its relationship with Leapmotor. Stellantis controls Leapmotor International, which is tasked with taking Leapmotor cars beyond China, and the two are growing closer, with possible European production in a Stellantis plant.

So, while Jeep’s parent is chatting to JLR in America, Stellantis is helping Chinese brands into Europe and looking at making some of their cars here. Somewhere in its head office, somebody must have a truly terrifying spreadsheet.

There is a serious reason for all this corporate courtship. Building cars has never been cheap, but developing electric cars has pushed costs into another league. You need batteries, motors, platforms, factories, charging technology and new supply chains. Then come software, artificial intelligence, chips, connectivity, assisted driving systems, cybersecurity and screens big enough to watch Strictly on.

Stellantis has just set out a €60bn investment plan for the next five years, including more than €24bn for global platforms, powertrains and technology. It also wants to reduce development time for new cars from as much as 40 months to 24. You do not need to be an accountant to see why sharing costs and know-how looks appealing.

It is also why Stellantis is reshaping its own family. Jeep, Ram, Peugeot and Fiat have been named as its four major global brands, with the scale and profit potential to lead the charge. Alongside its Pro One van business, they will receive 70 per cent of brand and product investment and be first in line for new global technology.

Chrysler, Dodge, Citroen, Opel/Vauxhall and Alfa Romeo become regional brands, using those global building blocks while keeping their own identities. DS and Lancia will be specialist brands managed by Citroen and Fiat respectively.

It might sound harsh if your favourite badge is not at the top table, but the theory is sound. Why develop separate batteries, software and expensive hidden parts for every brand when you can spend the money once, then use styling, interiors and tuning to make the finished cars feel distinct?

The Volkswagen Group has done that very well for years. Volkswagens, Audis, Skodas, Seats and Cupras have long shared expensive engineering underneath, while still giving buyers enough reason to choose one badge over another. Most customers neither know nor care which hidden components their car shares. They care that it looks right, drives well, works properly and does not cost a fortune.

Sharing becomes a problem only when every car feels the same, or when a supposedly premium model feels suspiciously like a cheaper one wearing posher clothes.

Plenty of others are trying the same thing. Toyota and Subaru have worked together on sports cars and electric SUVs. Toyota and Suzuki are sharing electric car technology. Ford has used Volkswagen electric underpinnings for the Explorer and Capri, and has now agreed to use Renault Group electric technology for new Ford models to be built in France.

Renault and Nissan, meanwhile, show that relationships can be long-lasting without being consistently happy. Their alliance has achieved plenty, but it has also had more than its fair share of tension. Like many families, they may work best when everyone has their own front door.

Some partnerships simply do not survive. DaimlerChrysler arrived in 1998 as a grand marriage of German engineering and American scale, before unravelling less than a decade later. Daimler’s partnership with Mitsubishi was not exactly one for the anniversary album, either.

Then there are Chinese manufacturers building their own families at speed. Chery is already selling Chery, Omoda and Jaecoo cars in the UK, while Lepas and iCaur are still to come. It is also working with JLR on Freelander, reinvented as an electric brand using Chery technology, starting in China with ambitions beyond it.

So JLR could collaborate with Chery in China and Stellantis in America. Stellantis could work with JLR, Dongfeng and Leapmotor, while Ford borrows from Volkswagen and Renault. It is less a car industry family tree than a plate of spaghetti.

Volkswagen is the master of making car families work together to make each brands’ cars better

And the new best friends are not always car manufacturers. Stellantis has also referenced work with technology and battery specialists including Applied Intuition, Qualcomm, Wayve, NVIDIA, Uber, Mistral AI and CATL. The companies shaping the next generation of cars may be just as likely to make software, batteries or artificial intelligence as vehicles.

For car buyers, none of this needs to be bad news. Done properly, it should mean better cars arriving more quickly and, hopefully, at prices that do not make your eyes water. Shared development can spread the huge costs of new technology.

But car makers need to be careful. Customers buy a Jeep because they want it to feel like a Jeep, a Range Rover because they want it to feel like a Range Rover, and an Alfa Romeo because, well, reason does not always come into it. Strip away too much individuality and the badge starts to lose its magic.

For now, the era of the lone car company is over. The next Jeep may be influenced by JLR. The next Ford EV may have Renault technology beneath it. A future Freelander will owe plenty to Chery. And the company helping to sell a Voyah in Europe may be the same one selling you a Peugeot, Fiat or Vauxhall.

It all sounds strange. But in a world of soaring development costs, fierce Chinese competition and rapidly changing technology, choosing the right friends may be the smartest way to keep your enemies at bay.

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