Have u used a p2p program like Utorrent?
If not, download utorrent (google it) and load your torrent into that.
That will download it properly.
Then extract the file it comes in
With that mileage I reckon you could knock it down a bit, especially if it's petrol. Check everything remember, kick the tires, check the oil, take it out for a drive and listen for any odd noises, and if the interiors in good nick. If you could get it down to 3000 then you have a bargain, but...