Well Islamabad police had to eat humble pie when a local driver contested the challan in an Islamabad court. There was a big news item in The News some 10 days ago. The man was challaned for using mobile phone while driving. The judge ruled that though use of mobile phone was dangerous, Islamabad police had to right to challan him as no law exists which bars use of mobile phone while driving. He advised the police to first get a law or an amedment in the exisitng laws made and then challan people.
I think same goes for shades. If you get a ticket, take it and just go to the court of Dr Ehtasham in Islamabad district courts and file a written complaint about it.
Ask any lawyer friend to study the Mortor Vehcile law for Islamabad and see of screen shades were illegal or not.
I use them on the rear windows, as they block the view from front windows. But so far no stopping by police. But if challaned, I will take the hassel of going to district court.
Now if you are stopped when using mobile phone while driving tell the thulla about it. But please do not use mobile for your own safety while driving a car.