Hi Ricky,
Did you ever get this sorted and if so what was the cause?
I have a 2013 Xf with about 45k on the clock.
I have similar problems and so far my Xf has been inspected in 3 differnet places. They all say they can see there is a problem but don't know what is causing it. They have even replaced the front bushes under warranty but this has had no effect.
I am convinced my problem started after I hit a pothole on the front left.
Any advice would be welcome.
Many thanks,
Jonathan