I want to share my experience of a drivers training with my Roadster, so that you don't make the same mistake I did. Last autumn I made a personal training with my Roadster. One exercise was to pass a spinning plate and to try to get your spinning car back under control. The area behind the spinning plate was very slippy, so the car moves around easily. But beside this spinning strip the track had very much grip. I passed the spinning plate 30 times and was able to catch the spinning Roadster for about 7 times only. So I often left the slippy area backwards to the area with much grip while trying to catch the spinning Roadster. Next day I realized that I have a rattling noise somewhere in the back of the car. Also there was another noise following the motors revs and one when cycling between acceleration and regeneration mode with the pedal. At the end Tesla changed the motor and the gearbox which took a while because of availability of sparing parts ! So I'm really sure beside all other exercises of this training that one with the spinning plate was responsible for damaging those parts, especially the backward moves of the spinning car to the grippy area. Tesla technicians said maybe the motor/gearbox already had some minor damages, but I didn't realize any problems before this training. So be careful doing such maneuvers.