Car assemblers can keep on increasing the prices. No problem. If an abc Civic costs 45 lac PKR for brand new, then they may take it up to 60 lac PKR for brand new in some time.
If you buy it at 45 lac PKR, then when it will be priced 60 lac PKR, of course your resale will be good compared to 60lac PKR. But the question remains; how many buyers will be there to buy it at 60 lac PKR? How many buyers will be there to buy the used one in 45-50 lac PKR?
There is a limit to inflation, and increase in car's prices. When it reaches or exceeds, majority stops buying brand new, and sales curve keeps on droping.