I had no alternate routes for years with standard Google Maps. A few years ago, I visited a park in Indiana, around 50 miles from my home. All roads clear. When I made my return trip, however, the only road back that I knew was closed, without any detour marked. Struggling to find a route via Google was no help, as she said 'Owensboro KY is possible via IN161, which is closed right now'. she offered zero alternate route. I ended up having to use a freaking compass and try any roads, mainly gravel farm roads, to find another that set me back a few miles, but on KY 60, which leads back to Owensboro. In the end, a compass, something that has been around since the 1400s, saved my butt, while the 'modern' approach failed miserably.
TL;DR, I don't trust Android Auto or most modern tech that depends so heavily on 'updates'. Some of which take important stuff away.
My own tip, always have a vintage solution to each problem. For me, at least, the look of a well-made compass or '60s stereo system not only has more character than a boring old soundbar or smartphone, but is more fun to use, you learn by using it, and to me the stereo from the '60s sounds better than a tinny little soundbar.