what about that mot thing? would that give the last few years result?

A lot of cars are garaged over winter, and not used dayly even in the summer. Having half of what another uk car might have is not that unusual

 

My 5 i've just picked up is a '91 and has done 68k miles so they are about.

 

The unfortunate bottom line is there is pretty well no way to establish mileage for certain unless you have mountains of old MOTs and paperwork. And its even harder, if not impossible with imported models. Hpi isn't accurate unless the mileage has been recorded with them very regularly.
The way I come to a conclusion about mileage is simply to have a good look at the car: wear on seats, steering wheel and gearknob are the obvious ones but also the condition of suspension components, engine bay etc. Even then its easy to get it wrong.
However, I always tell my customers to buy an MX5 based on condition rather than mileage. Here's a quick non MX5 example:
my wife has a BMW 745, '02 plate, nicely maintained but has covered 115000 miles; she cruises up and down the motorway, never goes over 80 mph, never brakes hard, never corners hard and covers probably 30000 miles a year like that. The car is immaculate in every way. My mother in law on the other hand has a low mileage Jaguar S-Type, only travels 1 mile to the shops and back and the car doesn't even get warm and she thinks that as it covers so few miles, it doesn't need servicing. I just can't believe that a car treated like that would be a better buy then our BMW.
Condition is everything and mileage is only one part of the story. Who cares what the mileage is if the car has been well looked after and maintained?

 

You could get the previous owner's details from the V5 and write to them (or see if they're listed in the phone book). Only applies if it's not being sold by the original owner of course.

 

I always went for the low mileage thing but in all honesty an engine and geabox can be replaced but rusty rotten bodywork can't. Best to go for the cleanest car, even if its done a lot more miles, unless you can find a clean car with low miles obviously.

Mileage can be so easily changed, especially on imports. 90% of the 'low milage' MX5's I looked at had one MOT if i was lucky so its hard to trace milage back.

 

Yer ill keep an eye on the car. Might go an have a look after i get some more info on the car