I'd qualify this statement to say that if you have music downloaded to your phone, you can still access it via CarPlay when you have no cell signal. Map renders can fade in/out as you gain/lose signal, but Gaia will randomly hold onto detail without signal, but can also lose the detail for no apparent reason, regaining it randomly a minute later, or an hour later when signal is regained. The Gaia app/CarPlay implementation certainly leaves something to be desired, but not sure if it's due to CarPlay or Gaia. OnX is also randomly marginal without service, but can at times work. I wish there was some sort of interface/settings for the CarPlay implementation in the LC.