All has not been plain sailing though. As reported last month, the A4 has had an intermittent hesitation under acceleration. I checked it in to Northgate Audi, Bury St Edmunds, who kindly lent me an A6 for the day, contacted me when the fault was found and even valeted the A4.

The problem appears to be with a sender located in the fuel tank. It's supposed to tell the engine management system that the fuel tank is nearing empty, prompting the computer to go into 'get you to the service station as economically as possible' mode. Hence, it cuts the rev range through the gears, making the car even more miserly than usual. This of course is very useful once the orange light has come on, but not when the tank is still full. So Northgate has ordered a new sender, which it will fit next month, and hopefully the A4 will return to its normal, unflappable ways.