My i3 Rex is producing a creaking noise when making turns. The noise comes from the rear of the vehicle. The noise is only evident when making turns which are approximately 90 degrees, and does not appear when going straight (and which is independent of any pavement imperfections or bumps). The dealer has looked at the motor mount and its bolts and says they do not appear broken. Any other ideas? They are going to take another look next week but they don't seem to have a clear idea on what could be causing this. I have put together a video (see below link) which includes the creaking noise.
https://drive.google.com/file/d/0ByV_ZWdrZrvVdW50aVpmTDZ4MWs/view?usp=sharing
https://drive.google.com/file/d/0ByV_ZWdrZrvVdW50aVpmTDZ4MWs/view?usp=sharing