What’s in a fob? The surprising complexity of designing car keys

With 905 horsepower and a 0-100kmh sprint time under three seconds, the Lotus Eletre is more powerful than a Lamborghini Huracan and faster than a Porsche 911 Carrera.

The US$230,000 (S$296,000) sport utility vehicle (SUV) is also the foundation of Lotus’ plan to electrify its line-up. So, designing the right key fob for it was… well, key.

It is an interesting subject – the fob. The way a consumer first interacts with a car is also one of the least relevant details of the driving experience. Yet, it serves as a handshake: A good design will communicate brand values, even status.

A lot more thought goes into creating a fob than drivers may realise.

“We didn’t want an over-featured key that becomes a big, bulky thing,” says Mr Mat Hill, head of interior design at Lotus.

BMW’s oversized “display key” from 2015 was a cautionary tale: A US$670 option with so many functions that it required a touchscreen, the gadget was discontinued in 2022 because of low consumer interest.

“It’s not about technology for technology’s sake,” Mr Hill says. “It’s about, ‘Does it actually make my life better?’ ”

For the Eletre, designers spent six months developing a smooth ceramic fob that resembles a guitar pick, also the shape of the Lotus logo. The grey device has one button, which locks and unlocks the vehicle. They nicknamed it “the pebble”.

It is ingeniously simple, handsome and – crucially, at less than 7.6cm across – small. “If you’ve got a nice suit on, it doesn’t spoil the line when it’s in your pocket,” Mr Hill says.

That less-is-more sensibility is a rarity in the automotive world. Fobs can now start a car as you approach; unlock the front door (and rear, separately, if you want); open the boot to varying heights; adjust the temperature; tell you if the windows are up; and give you the battery life and fuel range. With the rise of push-button ignitions, fobs are also functionally the keys too.

Things have come a long way since Cadillac introduced a radio-based keyless entry for the Allante in the 1980s.

A modern fob generally consists of an electronic circuit board, a battery and a switch pack that receives signals from sensors. Sometimes, a metal emergency key is hidden inside.

The design can speak volumes. Porsche 911 fobs evoke the silhouette of the cars themselves. So do the soft lines of the Mercedes-Benz smart keys that unlock E-classes. Volvo’s rectangular fobs recall the brand’s historically brick-shaped fleet. And at Audi, Ford, Subaru and Toyota, they have merged into a softly rounded coffin-like shape.

Still, others denote serious status, such as the ovoid disks from Bentley. The company spent two years and €1.5 million (S$2.37 million) developing the Continental GT’s fob to feel like the interior of the car. The key has a knurling pattern along its edges, just like the interior controls, and shiny chrome accents.

“We see the key fob like a business card for Bentley,” says Mr Darren Day, head of interior design. The brand’s “B” badging went on the top of the key because that is how people see it when it is left on a table or a bar. “It’s that first impression,” he adds.

A key that does not match the excellence of the vehicle works against it.

In 2025, when Cadillac premiered its Rolls-Royce competitor, the US$360,000 Celestiq, it included the same plastic fob found across the General Motors line-up, albeit in a leather sheath with stitches like a baseball mitt. Compared with the slinky lines of the hatchback itself, it was woefully incongruous.

Conversely, while the credit card-like “keys” for Rivian Automotive’s R1T and Tesla’s Cybertruck may repel Luddites, they match the high-tech feel of those electric vehicles. They also signal an inflection point.

“In the future, the key fob will be obsolete,” says Ms Rebecca Lindland, managing director of automotive at Allison Worldwide, a marketing consulting firm. Hyundai put fingerprint sensors in its SUVs as far back as 2019, while Ford is developing facial recognition.

Ms Lindland operates her Alfa Romeo Stelvio almost exclusively via the smartphone app. “The whole ecosystem needs to feel like an extension of my phone,” she says.

A low battery does not faze her the way losing an actual key does. It is always easier, quicker and cheaper to charge a dead mobile phone than to order a new fob. “At least with the app, there’s a support system,” Ms Lindland says.

In fact, Lotus’ Mr Hill says half of Eletre buyers do not even care how cool the pebble looks. “Early adopters are heavy users of the app,” he says. “A key can be a nuisance.”

His father-in-law, however, still wants to feel something in his pocket when he leaves the car. “It’s that bit of cognitive recognition,” Mr Hill says. And the pebble holds one clear advantage over his phone: With its tough ceramic shell, it will fare better if he drops it. Bloomberg