Hi Guys, I to have a knocking sound, it is noticeable on our rough potholed NSW roads and sounds like its coming from the steering wheel sort of like the nuts loose. I also have a rattle which sounds like its coming from somewhere around the centre air vent assy which is worse on the rough roads too. My Aurion has done 80,000k's and is 3 years old but luckily the dealer talked me into buying 3 years extra full factory warranty, so after reading this thread I will definetly contact Toyota and mention the steering problems and hopefully get them to fix it under warranty.