Asalam o alikum saleem bro, I recently went through the same process and after 2-3 months of struggle & same discussion everywhere here, with friends & family, I finally bought a Chevrolet Exclusive 2004 model in 4lac and I'm quite satisfied with it. Here's my detailed & sincere reply to your thread:
Cherry QQ is no doubt a good car especially in this budget of 3-4 lac where our current market only offers Mehran in this range. This is the car with very luxurious interior and some fantastic features like power steering, comfortable, power windows & auto windows closing on car lock, etc. I'm not much expert but after my recent experience, I think you should not spent more than 3.4 lac over QQ 2004. If we talk about demerits then Cherry QQ has very low resale, you probably have to wait long even with some loss unless you're lucky or car is well maintained & you're selling it at low price. Secondly no doubt availability of parts is not so easy as of mehran but its not a big issue as well.
If you wanna buy a car in the same budget then every one will suggest you Mehran whereas I & every one who prefers comfort & luxury over resale & easy availability of parts will prefer you cars like qq, exclusive, joy, vitz or to increase your budget. For me, Mehran is the worst car in such budget, if you've seen their recent advertisements then what they have to proudly offer are New Seat Covers & Both side mirrors :D, inshort they have nothing to offer to attract people in such a high price of 6.25 & 6.78 lac. On the other hand, the only benefit mehran has is good resal & easily/cheap availability of parts.
Third option you have that I adopted is to buy the real car of a popular company i.e. Chevrolet rather than a china made car with not so good local/international value. You can buy Used Chevrolet Exclusive(800cc) in 3.5 to 4.5 lac and Joy(1000cc) in 4.5 to 6 lac. Exclusive is Korea assembled car whereas joy a pakistani assembled. Both have extremely good & luxurious interior, comfortable drive, many features varies with models. Cherry QQ is its copy so why not to buy the real one rather than the copied? Moreover Chevrolet Pakistan Motors are also here to support, they have many authorized dealers all over the country. I can guide you for Rwp/Isb. Same are the demerits that resale is not so good unless you're lucky, your car is well maintained, or you're selling at low price. But it has more resale than Cherry QQ even I've seen people selling their Exclusives in just a week. Issue of spare parts but its also not a much big problem as Chevrolet Pakistan motors at Karachi delivers spare part to the entire country and you can easily get a authorized dealer or expert mechanic in your area.
You can find some very popular threads belonging to QQ at this forum. My suggestion is to confidently go for Chevrolet Exclusive in the budget of 4 to 4.5 lac.