Off or on?

I had a conversation with Abby today that went a little something like this...

Blanca: I went to my friend's house and I didn't want to go inside so I didn't get off the car.
Abby: Wait, what?
Blanca: I didn't get off the car.
Abby: Why were you on it?
Blanca: Huh?
Abby: Do you mean you got OUT of the car?
Blanca: Yes, I got off the car because I was in the car, DUH!
Abby: So then you mean you got OUT of the car?
Blanca: That's what I said.

So my question is, do you say "get off the car" or "get out of the car". I never paid attention to either one but "get out of the car" makes sense.  Anyway, just wondering. :)