Had my RX300 SE Navigator for 9 months now. No problems.

Couple of weeks ago after heavy rain the reversing camara picture was "Jumping" and "lines" comming down the screen like it had a poor connection. Following day the sun was out and no problem.
But the fault has returned. There are no other problens with the screen when using it for Sat nav etc all works well.

Any ideas what to look for, would like to avoid the Lexus Dealer if I can as I'm sure I'll pay bit time for them to find the fault.

Did the reverse camera come with your car or is it from some place else?
Sounds like a short in the wiring somewhere or maybe its getting wet a little bit since it only happens in the rain.

If it is only in the dark it would seem to me that either the camera is gone or you have a connection problem. The camera sends stronger signal when there is a bright picture (around 1.0v peak to peak) and it drops when the picture is dark (around 0.8v). So when the camera is gone and it sends lower signal in the bright light it may start loosing sync when it is darker. You can test it by just reducing the light camera gets and checking if fault returns.
Or could just be the connection.
Hope it helps
Thanks
Tazzz

I have the same problem . called the dealer and they told me it is a problem by more RX 300 and you have to change the camera. costs € 1200,-- anyone who have a other ( cheaper ) solution ?

Had a similar problem. Water had got into the camera. It was changed under warranty