How do auto repair shops get into the Google map results?
The map results are decided mostly by distance, relevance and prominence. You cannot move your building, so the work is on the other two: the right primary and secondary categories, services listed in full, accurate hours, photos of the shop and the team, and a steady flow of recent reviews that mention the work you did.
Alan Morgan Group tracks rankings on a grid around each shop, because a shop can rank first on its own street and not appear two miles away where many of its customers live.