Hi, try www.satnavishop.co.uk.
Depending on you XF’s age there are different options. I updated mine and tried to download it to a usb. It’s better to pay the extra and have them supply the upload pre-installed on an usb.
Mind you, installation takes up to 3 hours and is assigned to your car via its VIN number. The car has to be running whilst the installation takes place.
Hope this helps