Age limit of the car to be imported is 5 years, which means u can bring 2007 model car to Karachi Port by 31st December of 2012. On 1st Jan 2013 u will b able to import cars upto 2008 model only.
U can bring a car along with u if u r on deputation or working Visa but the tenure is 2 years.
@Stingray U have to make a letter from Pak Embassy, Trade/Commerce attache that u r earning money while ur stay of 2 years in that country and u can import one car after 2 years. In order to save urself from all this efforts u can get any car imported from Japan and pay upto 20000 Ruppees for Passport of a Paksitani laborer working in Gulf. All the cars coming in Pakistan are coming on these expatriates passports, this 20000 covers part of his air fare from UAE and Back.