@autophile, I think you are right on the corolla issue, I paid Rs. 1848/- for a 1586cc Liana because it fell in between 1300 and 1600, while initially the guy was trying to put in 1600cc and asking a higher amount, I did correct him showing the documents, so maybe @imtishal did not pay attention to what the guy is doing.
@naveed4speed similarly for the Mehran did you see if the guy marked it 798cc or 800cc?? Because Santro would be something 980+cc so the bracket is 800 to 1000cc and you will be paying the same tax.