Apple CarPlay - Cannot Adjust Vertical Icon Setting?

Hi all, I use Apple CarPlay to view navigation using Apple Maps, Google Maps and Waze. I tend to have all three running and like to swap between them to see how each is assessing my journey. What I cannot do is to have the icons for these 3 (or even just 2 of them) in the vertical set of icons to the right of the main window in my car display. Other apps (such as 'Settings') will persist when you navigate away from them, but none of the 3 above persist their icon if you switch apps. Can I control this such that (for example) I could toggle between Google Maps and Waze without the second touch required to go back through the main app listing? If so, how?? I do know how to order the app icons in the main selection window, that's not the problem. Any help gratefully received. Simon