PSA: If your Seal displays a message that says that your iPhone is not compatible and you can't open Carplay just soft reset the system.

To perform a soft reset, hold down the scroll wheel located next to the gear shift until the system reboots. You should be able to use carplay again with no issue. I don't know why this happens but out of nowhere one day my iPhone wouldn't connect to Carplay. Another friend had the same issue and this procedure fixed it. Hope it helps.