I agree to half you of your statement, if someone can get the licence from the government to produce cars in Pakistan. The trick would be to circulate the news in mass media about Pakistan MADE car applying for certification and that might help create pressure on govt to issue.
The thing if you start building a car in Pakistan you have to have it "Made In Pakistan" so you do not IMPORT a single part... believe me just make a good engine make parts from local market body can be crap (design can not) have CNG in it with almost half the price of Mehran with seat belts and it will sell like hot cake (with some adverts off-course)...
I will sell my Alto and buy a total "Made in Pakistan" car even if its crap just to support it.
So Id say,
Get license from the government (includes renewal costs also)
MANUFACTURE PARTS
Assembling process
Maintain price effective policy
Create dealers
Make availability of parts in local markets
Dealing with reputation problems/wrong myths created by big fishes in market