Tangentially, see Alexa is eating Siri's lunch at CES 2018, and HomePod isn't going to make a difference (Macworld)
"The world’s largest online retailer is seeking to remain in constant contact with customers by making its Alexa platform and Echo digital assistants as ubiquitous as possible. Amazon has similar arrangements with other carmakers, and in November it announced a suite of voice-activated work tools to bring Alexa to the office.Amazon's Alexa Voice Assistant Coming to Toyota's Cars This Year - Bloomberg
Toyota Motor Corp. joins Fiat Chrysler Automobiles NV, Nissan Motor Co., Hyundai Motor Co., Daimler AG, BMW AG and Ford Motor Co. in either letting Alexa into their vehicles or integrating the voice service into the connectivity systems that link customers’ cars and mobile phones. It’s a noteworthy development for the Japanese company because it’s been resistant to other big tech giants. The carmaker hasn’t offered Apple Inc.’s CarPlay or Alphabet Inc.’s Android Auto on its touchscreens."