wow what a dig,
Its been ages since i saw any post from Storm.
Any how why are u in the mood to change your car?Sounds like you already have a fine ride. If its not causing you any problem , don't let go. @ 57000 , it still can push out a lot more mileage. As far as trouble goes , any old Betsy will give you jalopy nightmares if a thorough background check is not made on its character. Different brands offer their own USP yet in case of used cars it come down to one word "condition".
You will feel a lot of difference once you shift from mehran to cuore. Do bear in mind this will include double maintenance cost though cuore is far better built , equipped and fun to drive. Mehro still leads as the queen of econo boxes.
Why dont you consider a cultus for that matter. Preferably 2008- 9 period efi model.
You havent mentioned your budget. Its best to get a brand new car if budget allows else look for a "great condition" used car.
Late night travel in Karachi is a challenging situation do recite Ayat ul Kursi and safr ki duwa , INSH ALLAH you will stay protected.