What was that movie called where there were these girls (3 or 4) who go somewhere (maybe mexico?) for a holiday, may have been spring break and accidentally run over and kill a homeless guy. The movie then focuses on how each of them cope with knowing they were in a hit and run and never told anybody. It would have come out in the late 80s or early 90s

I'm probably wrong, but it sounds similar to "I know what you did last summer" Though, I think that that movie had a number of male actors involved in the accident too... And it was about somebody killing off those involved... i.e. a horror movie...

Google search "I know what you did last summer trailer" and see if it looks right...

Like I said, I might be wrong...

The movie suggested came out in 1997, but the first bit is the same as your description, sort of...

2 girls and 2 guys are driving after a beauty pageant that one of them won. They hit and presumably kill a "Homeless person" (It isn't clear if he's homeless).
Fast forward 1 year. 1 girl gets a note that gets her worried about the accident. They all get together and start worrying, then people start dying...

Again, parts of it sound like what you want, but then the rest doesn't fit... Wrong year, slightly different plot...
Anyone else? :)

Dead Silence (1991) (http://www.amazon.co.uk/gp/product/images/B002G39LMW/ref=dp_image_text_0?ie=UTF8&n=283926&s=dvd)