What does a dream about people in a car crash mean I wasn't in the crash i knew the people then someone came up to me and said that they were going to die in another one the next day?

Such dreams are NOT predicting actual events. The people, the crash and even the car are all symbols representing other things. Generally speaking, this type of dream dramatizes the dreamer's anxiety about getting somewhere (the car.) It might concern actual travel but can also refer to moving into the future, moving up in the world, getting ahead, etc. The crash is a metaphor for failure and/or losing control.