I got all the CNG kinks and bugs fixed from the same installer! Now the car is handling like a dream on CNG. No more rattling sound (CNG kit securely fastened) and pick has improved dramatically (Advancer was not properly calibrated to my car, after making the adjustment to the advancer its working great - PVR advancer is absolutely fine for this car).
Now the pick is great even on AC+CNG (0-60 in about 13s). Its pretty amazing for a 800cc engine specially considering its much heavier weight compared to Mehran. This car absolutely rocks! no issues at all. Solid body, great ride and suspension, great seats, good AC, good noise insulation, better interior and finish than chevy, santro or Cultus, great value added features unmatched by any local car and everything works! I recommend this car to everyone. Best car in Sub-5lac category.