Golf 4 or Ford Focus

Hello dear Motor-Talk.de friends :O) !!! Have to buy a car soon before me and that is for the reason my old vehicle must be gone. Is a citroen c5. I have now thought of a used Golf 4 or Ford Focus, wanted to bring me some opinions from you in what you like so better, maybe the one or other has already gained experience with one of the two cars. would be great if you can give me some tips what kind of car of the two the reliable he’s achja it should be a diesel as I drive my 100 km to work every day