1. structurally rust free. bits of surface rust here n there wouldnt put me off
2. 16v

(or for insurance 8v

)
3. mileage, as low as poss, and as well looked after. id prefer a box of receipts for work done rather than a stamped service history
4. spec, as high a as possible - all this nonsense about things going wrong is just crap. all can be fixed easily if you know your arse from your elbow. and with a bit of simple yearly maintenance dont fail anyhow
5. PAS is a bonus but not an absolute. id prefer PAS everytime, but my current car aint got it. and you dont wear tyres out quicker unless you drive like a woman and dry steer all the time