Almost all Gen III Priuses I've been in have this in the front small windows: Does yours? What's the deal?
As a matter of fact I just noticed that today, then I see this post lol swyped from my Note II with Taptalk 4
Just to underline my comment above that it is "shipping plastic", I checked mine and there was a tiny bit left over when it was removed. I -suspect- it's there to prevent the window from being scratched when the dash or interior plastic is installed.
Mine had the shipping plastic left completely intact on the right side. It was shaped to cover the white felt-like material around the window. When I yanked it off a small bit remained which was removed using tweezers.
No! Don't remove THAT! It keeps the battery from discharging when the car is off. But if you notice any sounds before or after you remove it, when the car is running or not running, these sounds would be perfectly normal and no cause for concern.