After about month or so when I was on a little off road trip my lexus started throwing me annoying vibrating noise that sounded like from the corner of the windshield.What I noticed is after I wash the car noise goes off for some time but then comes back.Sometimes its more loud sometimes less.Noise does not appear when driving on smooth surfaces.I have no idea what could it be.It doesnt sounds like a dash noise but a windshield noise 100%. Anyone with similar problem or have any ideas where to look?Could it be a windshield wipers vibrating against windshield?

 

I had a Windshield Wiper fall off and another one came loose on a previous RX (4th Gen). The nuts that hold the WW secure were never tightened enuf.. Might be worth checking?

 

I have to take a look at it.I noticed as I turn wipers on sound goes away for that moment