everyone has been extorted by police in such situations as posted by OP.
It depends how many policemen are stopping you, what ride they have and if they have guns.
Thats why people don't stop at these check posts and then get shot at and die. Happened in islamabad and karachi.
A better way to deal would be to wait for them to ask what your father does and be like he is retired AIG or some crap. Act really chill and go like you're going to the police station to take this up with the SHO and will talk to ASP as well.Take their names, because they will not give you their badge numbers or ids. Names are usually on their shirt. Which ever area you are in make sure you memorize it because these cops are from the police station of that area.
Also note this is routine police behavior. They need to make ends meet and this is the easiest way to extort money from kids who are pissing their pants because they got stopped.
Mansha's son gave attitude to police in Nishat colony lahore and he had to pay a very heavy price 
