I had a 2003 VXR CNG White which I bought new in 2003. Drove it 36,000 km in 3 years and sold it. Car worked quite ok, except at 29,000 km timing belt had to be changed on G T Road near Kharian. A/C was not good and car would start over heating. So I drove with a wet towel around my head. Suzuki General Motors in Rawalpindi could not diagnose why it was heating up.
Apart from my experience, buying an old Mehran should be ok if you are ready for frequent visits to the mechanic. Repairs and parts are cheap and all mechanics can handle it. Just buy a car which is not accidents, rusted or with suspicious papers. Good luck!