Generally, I tend to recommend finding the book (or movie - works the same way) that you're looking for on Wikipedia and switch over to your language's version of the article to try and determine the translation of the title.
For instance, go to: https://it.wikipedia.org/wiki/Casino_Royale_(romanzo) - then start googling with added terms (like "romanzo" (novel) or "audiolibro" (audio book)). Here's the first result from "casinò royale romanzo" - http://www.adelphi.it/libro/9788845927010 - which should allow you to purchase it (and if not, will also tell you the translator, Massimo Bocchiola, which can help you in further googling).
Then do the same thing for the audio book and see if it exists (and there I'm not seeing anything, so it may not exist). If you can't find it, then you need to start bouncing around to other titles and possibly other authors to see what's had enough mass market appeal to justify an audio book release.