Trying to find a book for a friend but Idon’t have much to go on…

I’m just going to copy and paste her description of what she remembers here:
“a book that I read sometime between 1988 and 1992 (so it wouldn’t have been published later than that.) Don’t remember the title, obviously, or even the slightest clue about it. I found it at the library, I’m pretty sure in the horror section (that’s what I remember it being billed as.) I think it had a whole bunch of different characters all linked somehow.

Anyway, the scene I remember was this girl named Carol; I think she was a teenager or in her early 20s. She’s hitchhiking and gets picked up by this guy who starts hitting on her. He tells her to open up the glove compartment and pull out a handkerchief in there, and then he tells her he’d masturbated into it. He tells her how he’d pulled over to the side of the road and wanked (I think it was a British book, or at least set in the UK.) She concludes that she has no choice but to fuck him — I don’t remember if he actually threatens her or if he’s just bigger and stronger or what. But she tells him okay, if I make it good for you, will you let me go/not hurt me/something? And so she climbs into the back of his truck and lets him fuck her.

I’d really really love to know what book that was. Thank you”
If anyone has any idea of what this book is I’d really appreciate the help!

Source: reddit.com/r/eroticliterature/comments/b22w50/trying_to_find_a_book_for_a_friend_but_idont_have