^ nah Brother
It is of no use to buy a car from karachi as the difference is going to be of no more than 25-30,000 RS and besides that if ur gonna sell a Karachi registered car In rawalpindi or elsewhere in Punjab, ur cars Price will automatically be reduced!!!
So it is a better option to buy a car from Islamabad or Lahore if u want to use it in Punjab!!
Best of luck once more brother(Y)