With version 2.18.2 of the app installed on an iPhone connected to CarPlay, WhatsApp automatically appears as one of the icons on the CarPlay dash interface.
The new CarPlay integration means that Siri will notify in-vehicle users when they have received new WhatsApp messages and offer to read them out loud one by one. Users can also send WhatsApp messages by specifying to Siri who it is they wish to contact, then dictating the message. Siri will recount the dictated message to confirm, after which the user has the option to edit the message or send it on its way.
Apple's own Messages app has been a feature of CarPlay since the vehicle dash system was launched. CarPlay users are able to play back audio-based iMessages, have text messages spoken out loud to them, and also compose them using Siri. The difference with WhatsApp in CarPlay, according to iCulture, is that it doesn't enable the user to browse through a list of chat conversations.
WhatsApp is a free download for iPhone from the App Store. [Direct Link]