Get it warm and listen for a noticeable 'tick' from the engine (louder than the injectors). If so it 'could' be the head gasket. There is a weak spot and they blow through, but from the cylinder to atmosphere, so you don't get any water/oil mixing. They can go on for quite some time like it, but I wouldn't want to buy a car with the noise. A very similar noise can also be caused by the ex-manifold gasket. Again, not the end of the world, but a right pain to sort as it's always the rear bank that goes.

Front wishbones are unique to the ST200, and are more than double the cost of a standard Mondeo wishbone, so listen for clonks from the front end. If in doubt, jack it up and give the wheels a waggle. Any play and knock him down.

Really nice cars to drive - just don't expect much in the way of mpg! I got shot of mine because even driving it like Miss Daisy it barely did 20mpg, and if I got a bit giddy it would be in the low teens!!