Hi Mick,
First let me get rid of the idea that the X Type Jaguar is a Mondeo in disguise. This appears to come from the fact that the very first [and a very few were sold] were actually rebadged Mondoe Ghia's. I think you could count on a couple of hands and maybe a foot the number that went onto the road.
Sure, the floor pan of the X Type is Mondeo based, and the engines used are Ford engines, but the rest go the car is Jaguar. It is not uncommon in the Automotive world for cars to share parts. Even Rolls Royce from 1946 till taken over by the Germans had a Buick 5.0 litre engine.
The engines in the X type are tried and tested [I had a 2.5 Litre AWD petrol with a manual gearbox on an 05 plate] and the 3.0 litre petrol, although a bit thirsty, was the one that was bought in great numbers in America and Canada. They did like the All Wheel Drive!
The manual gearbox is on most X types, and is a pretty good one, and in fact seems to be standard on X type Sport models.[My son has one]
I have not done it, but apparently the sill covers are easy to remove,
Don't let people put you off. The Jaguar is the best car I have ever driven and I have been driving for 60 years.
Regards,
Peter.