Yeah that's a real shame especially as the A3, A6 & A7 have 4G LTE where the top of the range A8 doesn't.
I guess the D5 will have this sorted.
Paul, if you ever find a 4G solution for the 5F in the A8 please be sure to let me know!
Oh and I finally sorted the 2G/3G problem in my 2011 D4 so I now have 3G!
I part exchanged the car for a 2014 Facelift!
The 5F module details in the 2014 Facelift are as follows if anyone else might stumble across this in the future;
Part Number: 4H0 035 670 P HW: 4H0 035 670 P
Component: H-BNT-EU H47 0798
Coding: 020101000001F9EF7D368B1E00000003080001000000000000
-=Glyn=-