The problem is not the language. It's a problem with official/non official forms. That you will find in a country when you'll visit.

First option has to be official name. Terrassa is official, Tarrasa is not oficial.

Then we can talk about translations. For exemple, in French Catalonia (arround Perpignan / Perpiny�) all the toponym is in catalan, but is not official. I would prefer the catalan ones as primary, but I understand that the first approach has to be the official ones.

This is not a flame about languages, this a post about official forms has to be the first option.

Google has to give information. If you want to find in real live these names going by car, you won't. You will get completily lost.