Hardcore (1979)

Directed by Paul Schrader

A conservative Midwest businessman ventures into the sordid underworld of pornography in search of his runaway teenage daughter who’s making hardcore films in the pits of Los Angeles.

The first half is easily 4 out of 5 stars, let down by it spiralling away from Schrader in the final part (Tarantino is pretty good on this in his Cinema Speculation.) George C. Scott's daughter is a pale imitation of Jodie Foster's Iris in Taxi Driver (1976) as well. Speaking of women, the hooker-with-a-heart-of-gold Niki seems an obvious influence on Penny Lane in Almost Famous (2000); curiously another film partially set in San Diego. Perhaps Cameron Crowe was watching.