Plinking when braking

Hello all. First off, thanks for having this online community, I've been visiting since I got my first Prius last week. I've really been enjoying driving it, but something started happening and I wanted the thoughts and testimonials of others, before I take it back to the dealer to have it looked at tomorrow.

I noticed a few days ago, that *sometimes* (between 30-40%) of the time when I brake there is a metallic plinking sound, and directly under where I let my non-driving foot chill out (which is basically the center of the drivers site floorboard), my foot can feel the plink as well.

I've added a clip so you all can listen and give me your thoughts, because for the life of me, I can't remember if it has been doing it the whole time. When I noticed it first, it was cause I'd left my cell at home, and wasn't listening to anything on the radio, as when the stereo is on, it isn't as noticeable. I also drove a Prius as a rental a month or so ago, and I don't remember if it was doing that either. So I don't know if it is a normal sound, and nothing to worry about, or what, but I wanted to have as much knowledge as I can just in case they try to charge me anything. I've not even had it two weeks, and have only put a couple hundred miles on it.

Thanks in advance.

 

So I just got back from the dealer. No cost to me. No manufacturer defects. Just my own defect. Half full metal water bottle rolled up under the drivers seat….EMBARASSING

 

HA! I was confused as what y'all were thinking I meant. I'm about the last person who would own a gun!