📱 Android Auto 17.4 or newer: one switch to turn on, on your phone

Since Android Auto 17.4, the connection only works through Android Auto's built-in head unit server. Turn it on once, then this screen connects by itself.

1. On your phone, open Settings, type Android Auto in the search box and open the Android Auto settings.
2. Scroll to the very bottom, to the line Version (or Version and permission info).
3. Tap Version 10 times in a row, until a message says developer settings are on. The first tap only unfolds the line: keep tapping.
4. Top right, tap ⋮ (three dots), then Start head unit server.
5. Back in TaaDa, tap Start. When Android Auto shows its welcome screen on the phone, tap Continue (bottom right), never Exit.

After a phone restart, only step 4 is needed again.