Whining noise

[Jared2001]

My i3 is making a whining noise from the back when I step on the gas, especially when I'm going slow. Is there something wrong with the motor?

 

[Mondomensch]

Does it vary in loudness or pitch with the speed of the car? Can you have a passenger sit on either side of back seat to try to figure out exactly where it's coming from? Or if you drive past someone, can they hear it and where it's coming from?