I’ve got this setup on my car stereo (android based):
Cheap numpad from alibaba with mechanical keys (around 10 Euros)
T9 keyboard app from android.
Types in addresses into comaps way faster and safer than the screen keyboard and can navigate my mp3 folders easily to play music.
Yeah in my country where most people doesn’t speak English on the daily disabled the prediction and just typed like that on T9 dialpads. Can even text in class easily with a hand under the table