I've just got rid of my last daily driver, which was an '09 plate 2.2 diesel FWD X-type (I think all the diesels were FWD). I normally keep my daily driver 4 or 5 years. This one lasted 18 months before I cried "enough!".
First, it rusted. Less than 5 years old when I bought it, and supposedly a premium product, I should have found this aspect of the vehicle surprising. I had the rusty tailgate and crusty sills repaired by the nearest Jag dealer under warranty (6 years paint warranty on these things), but when I found that the spare wheel well was covered in surface rust I just tackled it myself - coating it in Zinc 182 once I'd cleaned it back to bare metal, and rattle canning it in satin black. It looked OK and never rusted again. I suspect this was never painted by the factory, given the state of what I uncovered. At best, it had a thin coat of primer here and there when new.
Secondly, the mechanicals. The second day I owned it the turbo went. Fixed by the dealer I bought it from under warranty, so free to me. Inconvenient, all the same and, again, a sign of things to come. It's also had various sensors go, as well as injectors and associated pipework and electrical fittings. Suspension bushes aren't great, so I polybushed the back end. It also eats tyres and wanders a bit in the wet, no matter if the suspension/tracking's right. Loads of Ford bits, but enough Jag only bits to make it expensive to run.
Thirdly, it developed a load of annoying interior rattles that had started driving me mental. By the time I got rid it sounded like you were driving through Chernobyl with a load of Geiger counters switched on and hidden around the car.
The bastard things also seem to cling onto their value well, so it didn't even have the compensation of being cheap for what it was. They're also appreciably less roomy than the Mondeo upon which they are based.
Verdict: Nice looking crap. And that's only if you like the look of old Jags.
That said, a 4WD petrol might be ace. If it was nailed together in the same factory though, I doubt it.