Prius C :: 2015 - Rhythmic Clicking And Clattering Coming From Passenger Side

Yesterday night I bought my first Prius--a brand new 2015 C2. All seemed perfectly fine till I was driving home from work this evening. I had the passenger window down and noticed a rhythmic clicking and clattering coming from that side anytime I drove past something to echo it back. This was going at about 25 mph in a residential area. It almost sounded like when you have some gravel stuck in the tire, except no gravel and it sounded more mechanical. It was very noticeable. No sound at all coming from the driver's side open window. I took it back out for a couple more drives to confirm that the sound was continuing.

When I drove it off the lot yesterday it had 40 miles on it--the dealer said someone had likely taken it home to show a family member, then brought it back. I truly don't remember hearing a sound like this when I test drove it, but the conditions were very different (other people in the car, window rolled up). I didn't notice this sound this morning, either.

The thing that is extra concerning to me is that on the way home tonight there was some roadwork where the pavement had been stripped from a section, then a large bump where the regular pavement resumed. I slowed down as much as traffic around me but still hit the bump much harder than I would have liked, especially for my brand new car. It was after that that I first noticed the rattling, a little ways down the road.

The car is making so many new-to-me sounds that I truly have no idea if this is just a normal sound or if I should be concerned. The tires look ok, I don't see anything obviously wrong when I look under the car.