I have owned a rx300 for three years no problems at all,the only ball joint problem ever on any lexus was the 95,96 gs300 .short of accident damage lexus ball joints are very good,as far as suspension the upper mounts on the 99 and 2000 rx300 did have a problem with the rubber seperating from the metal housing,this is a noise but not saftey related.I have been a lexus tech for 15 years and I am very curious as to the suspension,steering problems you have experinced.I am not being arrogant I would like to know of any unusual conditions ,lexus has a system in place for the diagnostic specialist from each dealer to communicate each day to the engineers any abnormal conditions we come across first hand,this system has huge sucsess in countermeasure and updated design very quick.My family has many auto techs in diffrent lines none of wich has the same commitment to perfecting product design and saftey as lexus.