2010 RX350 have the same problem with the oil running down the inside of the windshield. Normally the vehicle is garaged, but left it out for a few days in hot weather as I needed the garage space for a project. As stated it appears to be coming from the rain sensor and is running straight down the windshield. Thanks for the diagnosis.

 

This is the second time I've had a problem with the rain sensor on my 2011 RX350 leaking a fine stream of oil down the inside center of the windshield. The dealer replaced the sensor about a year and a half ago under warranty, and I'm waiting to hear if they will replace it again. Very annoying problem. Not related to glue problem described above, and vehicle is in a garage.