Vibrating Sound Near Front Wheel

Hello all...it's been a while since I've posted. I've got a silver 2011 Prius with just over 6200 miles on it, and this past weekend I started noticing a rattling/vibrating sound coming from the general area of the front passenger side wheel. The metal rattling/vibrating sound typically occur when I am initially stopped and then accelerate to around 20 to 25 miles per hour. As I push the gas petal and hear the gas engine start, sometimes I also hear this rattling/vibrating sound. I've briefly looked around the wheel, and I've also checked under the hood to see if the hood support bar was loose, but that seems to be fine. Not sure what else it could be, but I have an appointment set up next Wednesday with my Toyota dealer to have it checked out. Thoughts from the community?