Same problem with vibration at 37 to 45 mph. I've had mine back to the dealer several times. Once they wanted to replace the transmission, but the area rep told them not to. Went to another dealer and was told confidentially that Lexus is aware of the problem but does not have a fix for it, A little disappointing considering how much I wanted this car over a BMW or Mercedes. I have a 2011 ls awd which seems to be the model with the issue