Looking for an german vintage movie

Hello,
Maybe someone can help me.
I'm looking for a German vintage porn. The film is about a reporter who asks men about their sex life. Then the fantasies are shown. A young man wants a woman to do it with a candle, a man dreams of sex with three women.
The reporter gets a blowjob while driving a van.
The reporter's secretary always listens on the radio.
Does anyone have an idea what the film is called?
It would have to be from the 70s.

thank you

There is a film which starts off with a reporter asking questions of couple in the street (and later other people), but I can't match anything else that you mention - The film is Schulmadchen porno 1976