Four leading car brands have announced deals with three tech giants to add virtual assistants to new cars.
Microsoft's Cortana netted two of the deals, the others went to Amazon's Alexa and Google's Assistant.
The announcements were made at the CES tech show in Las Vegas.
One analyst said there would be a "battle of the giants" over the adoption of virtual assistants in 2017, since they can be built in to a variety of appliances.
Nissan and BMW have opted to work with Microsoft to bring Cortana to selected vehicles in the near future.
Ford, however, has struck a deal with Amazon meaning its assistant, Alexa, will feature in some of its cars.
And Hyundai and Daimler have said they will make their cars partly voice-operable with Google Assistant.
Ford has warned customers not to be distracted while driving and talking to Alexa
Apple's Siri assistant is already available in certain cars as well - via the firm's CarPlay software. Many brands - including BMW, Nissan, Hyundai and Ford - have produced models that support it.
Car-makers are interested in bringing such functionality to their vehicles as a means of making them easier to interact with - and to connect home appliances to drivers while they are on the road.
With Alexa, Ford plans to give drivers the ability to close net-connected garage doors, or to play an audiobook, picking up from wherever they had previously left off.
In Hyundai's case, Google Assistant will integrate with the firm's Blue Link software. Drivers will be able to start the car, adjust air conditioning, lock the doors or send destination details to the vehicle by voice alone.
A sample command given by the firm was: "OK Google, tell Blue Link to start my Santa Fe and set the temperature to 72 degrees."
The tech giants are vying for a place not just in your home - but also your car
BMW discussed a handful of ways drivers might use its digital platform, BMW Connected, and Cortana in future cars - including booking restaurant tables.
"BMW Connected can provide a reminder en-route of an upcoming appointment for which no location has yet been fixed," the company said.
"And Cortana can be used to make a suitable restaurant recommendation and reserve a table."
Toyota also announced a futuristic concept car at CES, the Concept-i. It features its own digital assistant, named Yui.
"It's really going to be a battle of the giants, starting in 2017," said Adam Simon, a tech analyst at Context.
"In exactly the same way that Amazon is doing a great job at the moment of building an ecosystem in the home, there'll be an ecosystem in the car,"
Microsoft boss Satya Nadella has said he believes digital assistants will change the web
Some car manufacturers, including Ford, are already warning drivers not to be distracted when using such products.
Last year, researchers at the University of Sussex found that using a hands-free device while driving was as distracting as picking up a phone.
"In the very long play we can see vehicles becoming a real entertainment space - an extension of people's lounges," said Jack Wetherill, a tech analyst at Futuresource.
"The real endgame is we all put our feet up and watch movies, the digital assistant does the driving."
In the short-term, he said that Amazon was likely hoping to encourage more purchases of entertainment content from its online store - such content could then be listened to in the car or watched by passengers.