Best setup: start Waze first with voice guidance on, then switch to SonoRev and leave it on screen. Waze keeps talking from the background, SonoRev tracks your speed, and the screen stays awake.
Waze on screen: SonoRev keeps making sound in the background, but iPhone freezes GPS for background web pages — the engine coasts on your last speed instead of tracking. That's an iOS limit for all web apps.
One audio route: iPhone sends Waze and SonoRev to the same output — phone speaker, Bluetooth speaker, or CarPlay. You can’t split them.
CarPlay: connect CarPlay first, then tap START ENGINE in Safari/Bluefy. If the car is silent, tap Play on the CarPlay Now Playing card (or the phone lock-screen media controls). Waze voice and SonoRev share the car speakers.
Audio keeps playing when you lock the phone or switch apps, and it shows up as media on the lock screen. It also plays with the silent switch on.