You need to bear in mind these cars were last made in 1990 mate so the youngest is 16 years old. Go over the car with a fine toothcomb, check EVERYTHING, lay on the floor and check the chassis rails, boot floor, arches, floorpan etc...........so take some clothes you don't mind laying on the floor in. Engine problems are the easy bit to sort, the bodywork ain't so my advice is be more pre-occupied with that. As Rick says you ain't going to get a minter for £2.5k...........not a chance and you won't find a S1 for that money, well, not one in one piece anyway.

Depends who mechanically minded you are - messing about with cars is one thing, rebuilding one is completely another, trust me. I've been there, done that ! And it costs a fortune to do it properly. Buy the best car you possibly can for the money you have but I'd get a bit more than £2.5k together mate. And DON'T buy the first shiny car you look at !