DPF problems seem common on cars which I believe make them ECC5 compliant.
As you say there have been problems with cars so fitted and it would appear to be an issue which other manufacturers besides Jaguar have struggled with.
When a DPF blocks up, it causes excess overfueling which causes the sump oil level to rise. That is not good as the fuel dilutes the engine oil leading to degradation of lubrication oil qualities. The net result is worn crank bearings which usually leads to an engine replacement.
It is interesting that Audi advise that some of their diesel models not be used to any high degree around town on a prolonged basis as this can lead to the above scenario.....
It is true that S-type and X350 diesels have been prone to diluted oil and DPF issues. I understand that X-types which are very much Mondeo based and use the same engines offered at one point the option to originally buy a car with or without a DPF filter. Something in my mind says that the 2008 models onwards were always supplied without the option to decide. One would assume that "with" would probably be the case for these later cars. Might be worth checking that.
This Honest John link has some useful views particularly in the later posts.
http://www.google.co.uk/url?sa=t&rct=j& ... tw&cad=rja
Mike K