in ios18 whatsapp does not appear in carplay
Carplay Whatsapp
WhatsApp is a third-party app; it's not an Apple app. It's likely that WhatsApp needs to be updated to work with iOS 18. Since iOS 18 is currently in beta, WhatsApp cannot release an update that would make it work with iOS 18. You will have to wait for iOS 18 to be released and then wait for WhatsApp to release their update for it to work properly.
Besides, if there is an issue with a third-party app, you should really tell the developer of that app so they know, and can fix it.