Well i just bought a belta 2006 in grey colour. Its drive is superb, better then platz(which i also have).
The general quality of Car is good, its has 2 air bags, abs,PS etc; features are awesome( better then local in terms of safety).
I got a Navigation screen and Two component speakers with it.I Added a software change and a chip which made the navigation unit a Dvd player.
Sound is also good. My platz also has 2 speakers, which came along with it but i added two more and its sound is just amazing. I'm planing to add 2 speaker to Belta also.
As for fuel economy, i haven't checked but it seems to be good too, i think its easily more than 13km/l. When purchasing your car you should get it checked with a good mechanic, so to find any flaws.
I have not tried Cng with it and nor plan to do so because Fuel average is aqeduately good and acceptable. Spare parts can be arranged in karachi but require a week or so if not instock. I have not ordered any sparepart as of now.
P.s the drive is great, it feels as if you are driving 1300cc when driving a 1000cc belta, believe me a 1000cc platz is slower than the 1000cc belta.
I just hope you get the picture.