I too have 2003 model mehran with 1 lac 20k on the odo, till now it's been doing great, but obviously with periodic and preventive maintenance.
Har dafa ye zaroori nahi hota k car band hi ho sometimes little issues become headache. A personal example, my friends owns a 2008 vitz which he bought in 2010, the car was only 17k on the odo and car's condition speaked for itself. That's why he paid more than market rate of ordinary vitzs. My friend takes care of his rides so much that he takes his car for check up even on a little tik tik sound.
Now coming back to topic, when the car clocked 55k a friction sound which was like faulty water pump sound started to come, he took his car for check up to the most authentic mechanic of the city (more than 10 years of experience at authorized toyota dealership now runs his own workshop). The mechanic said that it's the water pump issue, my friend made a special tour to Rwp and bought the pump for 5000, on installing it the sound was still there. Then the mechanic said that's its the compressor issue and you need to pay 15k and he can arrange it for you. By chance, my friend had to visit Lhr, when he parked car in a workshop there and started the engine, within seconds the mechanic said that its the pulley issue which is connected to the compressor. He also had the similar pulley of another jdm which he installed in 1500-2000 and car became fine.
This is just one example, a car is a machine. No matter what do u do it still finds a way to create a trouble, how many of us can arrange a special tour to Lhr/Isb just for car's repair and maintenance? Answer is 'not many'.
As I already said Lhr/Rwp/Isb/Khi jdms = eyes closed. Other cities, think 100 times before buying it.