Are we the only ones who got a Prius w/o problems?

Mine are actually rubbermaid 20oz bottles with screw on lids. The rattle actually comes from the bottle vibrating in the cup holder in the center console area. I also periodically get the rattle from the sunglasses in the other cup holder because that darn flip down glasses holder in the roof of the car isn't wide enough for my sunglasses.

I could actually see that the little seal ring could rattle a little, though I wouldn't be surprised if what you heard wasn't just the entire bottle vibrating in the piece of plastic.