The 3 lt is a very fast motor. The engine is very different than any Mondeo The engine is the same as that used in the most basic Mustang. Some parts are the same as the Mondeo around the chassis and suspension but not much else. Jag parts are very expensive best get aftermarket bits realy apart from sensors and most engine bits. I am still not sure what to do with mine after I fix the rear end of the drive. Horrible grinding noise. I may keep it, havn't realy made up my mind. Depends on how confident I am when I have sorted it.
With the current values being pretty low I would maybe keep it as its comfy though cramped and a hell of a fun car to drive.
I would say to anyone contemplating buying one just pay a lot of attention to possible rust areas. If you stand quietly and listen carefully you may hear the rust chewing at the metal.