Airlink,
Direct Line told me the XF was in the same insurance group as my Voyager. The Voyager is a confirmed 15.
However searching the net does seem to indicate that the XF is an 18 -
http://www.carpages.co.uk/guide/chry...-v6-manual.asp
I don't know if Direct Line have it wrong, but I seem to have a good deal (for once).
I hope you like your XF.