My personal pet peeve: using the wrong language for the region. So, I'm a native English speaker - but I'm driving around Germany. Give me the names of the streets in German only - NOPE.
Still can't find any way to fix this issue. Its terribly annoying.
When a German street name is synthesised using English settings, its a proper butchering. Just not good at all.
I want the instructions in English - but I want the place-names in the native language. This is the only sensible way, yet none of the Maps vendors seem to have understood this. Do they not use their products?
Semi-related anecdote: A few years ago, for a while Google Maps insisted on labelling White City (in London) as "White Stadt" and the M25 as "Autoroute brittanique M25" (and not just for French users).
Still can't find any way to fix this issue. Its terribly annoying.