We just bought a certified 2012 RX 350 last month. The car has 31,000 miles and in great shape. The tires are also new. We loved everything about the car except the bouncy feel ride especially felt on the passenger's side. Unfortunately we test drove the car only for 10-15 miles and had no issues at that time. We just went for a road trip for 120 miles yesterday and my wife felt the bouncy feel ride more prevalent than ever before. I thought that you do not experience this in a Lexus!!! Granted it is not a brand new car , they do go through the certified car with a fine tooth comb.We called the dealer and they want us to bring the car back so they can evaluate the issue. My sales guy thinks it could be anything from struts, shock absorders and etc. He said there were no known problem with the car but they will stand by their warranty. Any feedback ??? Thanks in advance. Noel