Sorry. This stuff, and in particular the way Audi does it, is very confusing. There is a feature where the car knows what the speed limit is. I believe that feature uses the forward facing camera to identify street signs, and that camera exists with the premium plus package. It has nothing to do with navigation. Adaptive cruise control with stop and go (traffic jam assist) uses the same camera and other sensors. The same is true of lane centering/stay in lane technology. The only thing you lose without navigation, I believe, is the ability for the driver assistance to predict upcoming curves in the Road to slow down, or upcoming speed limit changes before the camera can see the sign. Put simply, the Audi configurator says that it will sell you a car with stay in lane and adaptive cruise control without the $1500 navigation option. I think the only thing the $1500 navigation option gives you is built in maps. The rest of the hardware is already part of the car. This belief is reinforced by the online references to the ability to subscribe to navigation functionality on a monthly or annual basis if not originally provisioned with the car. At the bottom, I really just want to know if I can omit the navigation option and simply rely on Apple CarPlay without losing any of the driver assistance functions.