While we're on the subject, how do you tip for valet parking when staying at a hotel? For example, if I stay a hotel for 3 nights and thus do three nights of valet parking, do I need to tip for every time I pick up the car, or only when checking out? I've been stingy on this before because valet has cost me more than $30-$40 a night, but I don't want to be rude either. I just don't know what the proper etiquette is here.