Not sure about karachi/ sindh
I am a frequent traveller on M2 motorway lahore - Islamabad
very common to see unregistered applied for .. on this segment
My brother got his corolla registered after 2 years , june 23, with many trips to mianwali , DI KHAN , ISLAMABAD etc
2x times paid fine of PKR 750. On motorway entry point
Both times it was sial interchange