I was in same in same situation 3 weeks ago
make sure documents are genuine and complete, get them checked through excise office
tokens are paid (if not deduct price from total agreed price), TO form is present of last owner
check for number of owners and Tokens info by entering car registration number here
http://mtmis.punjab.gov.pk/index1.jsp (bottom of page), try another format if one doesnt work for you. when I was checking, it gave error with lec-xxxx, but i entered lec-07-xxxx and it worked
if you want resale, get car which is not showered from inside.
Its not too rusty. check for it at different locations, take out carpet it will give you better view
seals of body are intact and pillars are not repaired.
engine is is good condition and doesn't require any major work soon. ring piston head etc. (dont settle for engine in not very good condition)
tyres are in good condition, if not deduct price as you will require new soon
for engine, body, tyres you need a good mechanic, and denter/painter,
they will cost you some money around 5k but be sure, this is worth the effort and money
or visit suzuki center, they inspect your car thoroughly for 2-3k ( they will exaggerate that its not very good condition require this and that)
Once you find one good condition car, InshaAllah
get all filters and oils changed. get the radiator serviced and properly inspected, and the car service too.
Now you can go ahead with your ride
Good luck to your purchase