One of the first ModelS owners in China just had one of the cardan joints cracked completely during stall parking. It is unthinkable if this happens when the vehicle is moving at high speed. Tesla service center then replaced all 4 cardan joints and responded that 'the cardan joints were improved in 2015'. In China a couple of owners (delivered in 2014) experienced similar issue. Some owners claim that if the steering wheel is pushed to extreme, they will hear loud noise coming from wheels and the car would be bumping up and down like a boat in waves. This has not been the case for ModelS delivered in or after 2015. Then the speculation is that there could be potential design flaw that lead to severe security concerns for ModelS delivered in 2014. Anyone on this forum encountered similar issue?