now there is a catch. To keep a car trouble free, u need to know how it works and in case it breaks down the sequence to fix it reliably.
Unfortunately, only a few examples would have been left there which are perfectly maintained and wont need any maintenance for some time in your given budget and criteria.
In old cars, conditions matters more instead of model, make and variant ( thank you Suneel Munj sb ).
better look for a car which is kept in pristine condition and dont carry signs and marks of butchery and battle with ustaads ( with apologies to ustaads out there ) .
in 1 million budget and sedan, i think look for a perfect Margalla Plus having powered steering locks etc. Being old model there are chances that you find a decent looking margalla in your budget as baleno is out of question.
forget about fuel consumption, as all old model sedans 1300cc and above wud return u 10/11 KML for within city drive.
my 2 cents