Originally Posted by MNBoxster

Hi,

As I said, it may work on some older cars, or companies which still use polarizing as a means to block UV, but this is phasing out.

Polarizing is more expensive to manufacture and it reduces the total light transmitted through the glass which can be especially important for nightime driving.

To help combat this, the glass is generally less polarized and so the UV protection is more on the order of 75% or so. It's a trade-off between overall light reduction and UV protection.

I too wear polarized Sunglasses and there is no blocking on the Boxster glass, when rotating them as you mention.

Still, your post was thoughtful and very informative.

Happy Motoring!...Jim'99