Let me begin with the title, the Hitchhiker's Guide to the Galaxy.

When the 2005 film came out, as far as I know, it was first translated into Chinese as《银河系漫游指南》, while, in 2011, when the trilogy of five was published in Shanghai, it was 《银河系搭车客指南》. Both have 银河系 as "the galaxy" and 指南 as "guide". The first got 漫游 which means (I suppose) "to travel aimlessly and freely" while the other got 搭车客 that has a meaning closer to "the hitchhiker". However, there's not such a hitchhiker culture in China, so I personally prefer the first one, no matter how exact the other is.

In French, as I've found on Bing, there are also more than one editions: «le guide du routard galactique», «le guide galactique» and «le guide du voyageur galactique». It seems that the last one is the most popular right now.