Yep, I'll have to remember to try rotating next time
I guess sunglasses will already be set up with maximum glare filtering when they are the right way up on your face, may be worth tilting them a little bit each way - interesting thing about polarising lenses is that if you get two pairs of polarising sunglasses and place lenses at 90 degrees to each other they go black (cut out all the light) as you twist them back into alignment the light comes back - I have used this in the past to look at solar / lunar eclipses - I like polarising glasses for driving because even with a light yellow or brown tint they cut out lots of glare - problem is they can make rainbows on the surface of or darken the LCD displays in the car. with older cars with 'toughened glass' windscreens instead of laminated glass they did show up the patterns in the glass, could be quite distracting.
grey tinted ones best for photography as colour is neutral, other colours will result in tinting of the final photo (colour cast).