Punjab Registered
Lahore
Multan
Faisalabad
Rawalpindi
Mostly Lahore registered vehicles are preferred then comes all other cities people who are locals of that area mostly get their cars registered in their own city but Number is really less.
Punjab registered Cars are trouble in NWFP or KPK and Baluchistan....
totally okay in Islamabad and acceptable in Sindh
NWFP or KPK REG
They are only okay In KPK or NWFP and acceptable in northren areas to an extent
ISLAMABAD REG
Acceptable in PUNJAB, SINDH and most parts of KPK or NWFP Like Peshawar, sawabi, etc etc
NO GO in Baluchistan
SINDH REG
Works IN Baluchistan pretty well and okay in Punjab and reasonable level of tolerance in ISLAMABAD
Not okay in NWFP or KPK
Baluchistan REG
Works in Baluchistan only and almost 40% cars used there are sindh reg and 40% quetta and rest are NCP
AKJ
Only in AJK and acceptable every where except Baluchistan because mostly people get really good deals there
Note: these are my observations if you like to add something then plz do