The only two scenes I recall were of a young black woman who might have been a vampire about to kill another girl looking away, and the other were the same young girl running away with a young guy being chased by the vampire/monsters, locking themselves in to a car while trying to destroy a ring by lighting it on fire.

When the guy destroys it, every one of the monsters/vampires disappear, including the girl in the car. I saw this movie as a child in the mid 80s but the film could have been older than that. Please help!