Hi Jack,
I'm sorry I'm not sure where you want me to check the use of "Usine", excepted on the Menu of course. In Finances I can see "Siège", which could also be replaced by "Usine". May be this was what you were expected to.
In addition, also in Finances tab, there's a button "History". There's a mistake, the right translation is "Historique". You also can take a look on the speed unit: My opinion is that "KPH" could be replaced by "KMH", buy may be this will work for French users only.
Finally, when you'll have time, you'll can apply some translations on the Race viewer. Thanks for your time!
@Mathias: Pour toi, "Bâtiments" a plus de sens que "Usine", c'est ça ?