@Georgios Hi Georgios, I personally use the Navigation app as a backup navigation tool since my car has a built-in GPS device that indeed has a big screen. Once we're able to develop for Apple Carplay and Android Car I'll probably activate Carplay and download Navigation in my car. (fun fact, we've re-applied AGAIN with apple. Hopefully, this time they'll respond). When we do riding tests (for example this one with an absoutely bomb photo of me and Daniël (the lead developer) at the end of the track) we use several (up to 8 running simultaneously) devices all mounted in a bracket in the back of Michel's Jag. As for battery usage the phones by CAT hold out pretty well, although older models may run the navigation app a bit slow.