Movie about two men riding a car and meet a girl who offers sex to find a best one.

Hi,
i can’t find it and only what i remember is:
-young man meet older one
-young man is looking for somoene/going somewhere
-they ride together in a car (red cabrio?)
-the older one is some type of mentor for the young one

Main thing: they meet a girl standing next to road and looking for a ride to somewhere. She offers sex for young one, because she is looking for best experience and so far had about 1000 of them, but she is not happy yet (seems to be a nympho). The young man wants to agree, but old man says that thing which come so easy can’t be good, so the young man refuses (and being happy after all).

This movie is something between 1990 and 2010?

Thanks a lot!