Can the police hold my car and press charges after they released me?

I had a friend drive my car and a friend ride with us to the lake to put money on my boyfriend’s books. On the way back, we were stopped and the cops arrested the passenger for possession and let me and my friend go. Now they say they have a hold on my car for investigation but there isn't anything in my car illegal and all if my clothes and purse are in it. I called them and asked them what I need to do to get my vehicle back and my belongings but they said they were keeping it , would probably seize it and was considering pressing charges on me and my friend because they thought we know the passenger had drugs on him.