When I purchased my 2011 RX350, the sales guy told me the following about the windshield/front windows:

1. The glass filters all ultraviolet rays so the leather seats will never fade under sunlight and our skin will be protected from ultraviolet rays. Is this true or hype?

2. The glass external surface will cause water or rain to roll off. I can see that when it rains. Is this a permanent feature of the glass or is this simply Rain-X compound to which it will wear off through time?

 

1) I believe most modern auto and window glass cuts off a significant portion of UV, so it's generally true except maybe in the case of someone that has a very high sensitivity to UV.

2) It's a coating (Rain-X or others) that will eventually wear off.

 

Hasn't yet, my 2010 (h) still sheds the water like it did new. W/S and driver/passenger side glass.

 

Yes , UV is blocked by the tinted windows - the transition lenses on my wife's glasses will not darken .

 

My 2010 Rx was bought used, but it still beads the water and rolls off really quickly. Love it!

 

The manual advises you not to use an abrasive on the driver's / passenger's front windows. So whether permanent or not, proper care will extend it's beading effect. I've noticed no harm with traditional glass cleaners, but I avoid clay or polishing compounds.

 

I found this thread but it doesn't look like the information was confirmed. The manual says to avoid parking in the sun for prolonged periods of time to protect the leather. I use a sunshade and dash and leather cleaners with UV protection. As far as the glass repelling water, I can't comment since I have Rain-X on the windows,. I've used clay and Glass Scrub without issue. Sometimes that's the only way to get rid of the water spots. BTW, the manual also recommends washing the interior tailgate window with water and a soft cloth instead of glass cleaner to avoid damaging the defrosters.

 

https://secure.drivers.lexus.com/lex...ter-Protection