Seems there has been a problem with Lexus for years with water leaks. that they don’t know how or can not be bothered to fix. Distgusting for a car like this. Three years ago I purchased a 2004 RX300. Good history only 45,000 miles. After couple of weeks screen started to steam up over night. Searched for over a year round front of car for water. Nothing on carpets, etc. Then left it. Still steaming up windscreen. Six months ago had reversing sensors put in by local mec. They started playing up. Stripped out back myself and found 2 inches of water. Have followed this forum and tried moonroof drains. Seemed to be ok but I duck taped the moonroof to elimanate. Drained water from boot - rained- full of water again. Cleared water from boot. Took rear lights out- seemed to be ok, but sealed with mastic and replaced. - Rained- Full of water again. Checked plastic one way rubber valve that lets air out when you shut the door. Sealed round it. -Rained- Full of water again. Checked seam above boot After reading the TSB's, it stated that RX's suffer from the seam cracking above the upper back door strut mounting, sealed it -Rained- Full of water. Took strut mounts off, resealed -Rained- Full of water. Got out my camera and took photos of everywhere that I could not easily see, (Mid 70’s bad back etc.) and these are some of the photos I got, pointing the camera towards the back of the car, very low down. You can see the water running down from seam. Hope they may help someone else who has the misfortune to have one of these cars. I have not sealed yet but I am going to seal from inside car with some type of seam sealer. (If it ever stops raining) I just hope this is the problem.