90% of the times this has been fiddled with.

I believe most of them are tampered with once the car gets here so you can trust the ones you see in Japan but not in Kenya. But maybe I am just being naive about the Japanese, but hapa kwetu it is a poorly guarded secret.

I personally treat cars whose mileage works out to less than 10,000 km a year with a lot of suspicion. In my view, it is possible but not likely.

That being said, the single greatest risk I see with driving a fake mileage car is inadvertently neglecting to change your timing belt when you should. Granted that many cars will carry on for thousands - some even tens of thousands - of kilometers after when the manufacturer says you should change it, it is not a chance you want to take if you can help it.

In my opinion, a 7 year old ex-Japan car with between 70,000 and 120,000 km is a good buy, though in general the price should go down with the mileage. Lower than that I would smell a rat. Higher than that I would start worrying it might feel a tad too old. Rattling parts and all.

Still, I have seen a good number of decent, high-mileage off-roaders. Old-school Mercs and Volvos too. For those I would make an exception. But nothing beats personally checking out a car yourself if you can. With a bit of horse sense and good old Google, you should know how to spot the common signs of trouble. You don't need a mechanic to see that a car has an oil leak for example.

My two cents.

in some cars, if that belt snaps while the car/engine is running.. it may damage the pistons and valves as well as affect other components.... crankshaft, connecting rods, camshaft.
In all cases, when the timing belt fails, the engine instantly stops.

If you're not sure, have the timing belt changed, regardless.

At 100,000 kms is the general rule

Also check the exhaust if oily or smoky especially on start - up know the rings & valve seals are nearing their end life even though the car mileage says 30000km

What about vehicles having a timing chain i/o timing belt?

Leave it alone. Those ones are generally designed to last the life of the car. Still, RTFM

chains are meant to last a lifetime but some don't. For such you wait till you hear the krrr sound you know the chain is slipping or you open the cover and inspect it kama chain ya bike

Thank you for the cost approximation!

I would not personally consider the mileage as the most important factor while purchasing a second hand car. Whereas it is a pointer of wear and tear, it is the maintenance of the vehicle that matters most. I know of a Mitsubishi pajero owned by an institution and has been used since circa 1989. It has done about 570,000kms and several people have been waiting for its auction, even though it seems not forthcoming. The point is, maintenance and the condition of the car are the most important factors to consider when buying a preowned car. This might be hard to establish when importing though because it can be a low mileage car previously involved in some serious accidents. If possible to get a history of the car, and do a physical inspection of the car, i think it would be most helpful.