Have taken the A4 on a road trip. Currently in Ukraine and completed the journey from Norwich without any hiccups.
We covered 1316miles in 24hours of driving time split over 2 days. Trip computer says we averaged 55mph and 37.6mpg. We did hit 38.5mpg but then dropped with the air con on full to counter the 35c sunny Polish weather.
I really missed the A8 on this trip, especially as the A4 doesn't have cruise control. Overall no complaints with the A4.
Here's a photo when we parked up after crossing the Polish Ukraine border to buy 3rd party insurance.