I'm upset at my parents for a car accident that I got into
How is it their fault?
I was in the car with my dad.
That's understandable, people should always take responsibility of their actions. You should tell them how you feel.
That's the thing I don't feel like my parents deserve what I'm going to say.
Maybe you could soften your words. The car accident caused you emotional trauma, and letting them know may lead to you feeling better and them helping you work through it.