Read this in the voice of Comic Book Guy. It helps get the point across.
No, no, Mr. Underage Drunk Guy...take our car. We don't want it. It's more important for you to get your party on than for us to drive to work or anything like that. So go ahead...turn down imaginary streets from whatever lane you want. We don't mind. As long as your car can still drive, everything is a-ok.