Ive got factory tints on mine too and when i put that thing up and can see pretty much buggar all out the back!!
Yep i have it up all the time when got my little girl in the car, does shade the rear of the car slightly, But im having all the rear windows tinted on thursday so prob wont use it after they been done.....
Ha Ha, was thinking the same, never used it.
Not much use to me, especially as the car has rear factory tints.
In fact I get a knock from that area when I hit any bumps and Im unsure whether its the parcel shelf itself or the visor?
I found the best use of the shade is when driving at night, it takes the glare aware from the auto dimming rear view mirror and you can still see the cars behind you. Other than that its useless.