I have sync 3.4 on my ford F150 - CarPlay does not work with iOS 18.1. Sync says I don’t have anything connected. Something is up.
iOS 18 Apple CarPlay
Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software. I'd greatly appreciate it if you could open a bug report, include a sysdiagnose, and post the FB number here once you do. Bug Reporting: How and Why? has tips on creating your bug report.