Update:
I contacted THULE and this is their response.
"Unfortunately our engineers have been unable to approve a recommended roof-rack solution for the Jaguar XF as the angle of the roof-edge is incompatible with any of our Thule products.
It is possible that Jaguar have developed their own solution and so our only advice is that you please contact them directly. "
It would seem therefore that Jaguar have redesigned the roof line, and as such, no "Aftermarket" product is yet suitable or tested. I do believe though that once opurchased, then aftermarket attachments can be fitted to the Jaguar Roof bars, such as Thule cycle carriers whcih are cheaper than Jags own version.