Parked Prius- making awful sound from brakes? Suspension?

First off, I am aware of a few other threads have posted about the Prius brakes squeaking etc. However, I am not sure how to describe this one- or if anyone else has come across this situation.

Background: 2010 Toyota Prius, roughly 45k, purchased new- Columbus, OH
Routine service has taken place, most recently was an oil change in February. Based on the normal inspection at the local dealer, nothing was noted as needing service. This situation noted below began a few days ago, not sure if its a weather change? moisture? or what?

Situation: Drive the car 10-15 minutes to the office, pull into the parking spot, press the "P"... get out. As I am getting out of the car, the car rocks slightly back and forth; however, a horrible squeal is present as its rocking. If the emergency brake is applied, rocking is reduced to nearly zero; and the squeal is minimized but the not completely removed. Let the car sit (without the emergency brake on) for 30 minutes, come back to the car, push it on the bumper and back and forth- no sound. Go figure right?

Well, below is a hyperlink, made a quick video after pulling into my garage after work- take a listen, any thoughts or suggestions would be welcome to what is causing this groaning squeaking sound? Note- Prius is scheduled to go in next week - but a heads up on what I am walking into would be gratefully appreciated.

Thanks,
- Chris

 

Car is scheduled for Monday service at Toyota. Yes, when you put the car into park, open the door, and get out, the car rocks slightly- however, you can hear that noise as its rocking slightly. Also, when I pull into the garage and slow down to a complete stop, and sit for a moment with the windows open... you can hear some groaning/ squeaking coming from the same region. Video was of of me, pushing the car slightly back and forth.

Thanks for the replies back! Chris

 

Update: Car went in for service Monday, picked it up today. Local dealership performed several drives Monday, of course the sound didn't appear at first. However, at the end of the day, the technician was able to hear it but not able to pin-point-it. Today, technician was able to locate it and determined the sound to be coming from the down pipe exhaust gasket. Simply put, after driving the car, the gasket would rattle back into place when parking/getting out of the car. Go figure, Toyota covered replacing the gasket, charged only for the hr of labor.