Recently I have updated my mobile version to iOS 18, since the day maps are not working in Apple Car Play since the update. The car display shows the message directions are not available in your location. Before the update it was working perfectly fine.
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 and post the FB number here once you do. Bug Reporting: How and Why? has tips on creating your bug report.