car / du fait que / parce que
What is the difference?
"Car" and "parce que" mean basically the same thing, though "car" is a bit more formal and is usually found in written French, while "parce que" sounds more natural in spoken French. Please note that you can never start a sentence with "car", while it is perfectly possible for "parce que".
"Du fait que" means basically "because/due to the fact"
I was taught that car was a formal/written term, but I hear it all the time in spoken French in conversation and on the radio
About.com has a very nice article about the differences between parce que/car/puisque/comme: http://french.about.com/od/grammar/a/conclusions.htm . I find it very helpful.
I think "car" is more formal, whereas "parce que" isn't. Think of it like this: using "car" would be like saying "I eat, for I am hungry", and using "parce que" would be like saying "I eat because I am hungry".