I had almost the same problem with my es , the drives side would go down when it wanted to and always went up , the passanger one would go down but not back up from the drivers control. The problem was the switch , I called lexus the part price I got was $502, the shop I take it to was able to clean the existing switch and get it working again perfectly for now. Only charged $40 too. This problem originated because I spilled pop on the pannel last summer .. took almost a year before it started giving me problems.