The "passenger part" of the car ("habitacle" in French, I do not know how it is called in English) ?v=F06LjugtIUo&NR=1
"Passenger copartment" usually
Also, a little different in definition, there's the "Greenhouse" which is the whole area above the beltline (i.e. all the windows and glass, a-pillar, b-pillar, c-pillar, etc...)
A proper definition:
http://en.wikipedia.org/wiki/Greenhouse_(automotive_term)