One problem related to rear suspension has been reported for the 2009 Lexus IS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Lexus IS based on all problems reported for the 2009 IS.
The rear axle vibrates on my Lexus Is 250, causing serious visibility Issues in the rear view mirror and a very unstable ride at highway speeds. . The Lexus service manager says that this problem also existed in 2008 and 2007 Lexus models. So they acknowledge the problem but refuse to do anything about it.