Usual suspects:

Wiring loom can give issues
Fusebox
Main loom plugs under bonnet vent
Front bushes are crap, leads to erratic handling & poor tyre wear
Some P8 ECU's suffer form 'P8 syndrome'

Most of the above common problems would have been fixed by any caring owners Other than that, they generally fair better than other 'normal' escorts of similar age, as they are usually looked after. But as with any car, do all the checking you can etc, as some can afford to buy them, but not run and care for them properly....