Averaging 21-22 in my RS6 but thats mostly local driving and the bitdi got around 35-38 mpg. getting in the bitdi even after driving the RS still feels so smooth and effortless and a joy to drive. Probably why im still torn about selling it.
Scrutinise the service history, Look into when the gearbox will need an oil change; factor that into price. MOT history all tally up? What warranty work has been done on its at all possible to see these days do to the secrecy act. Any painted panels? Check the rear cubby areas and spare tyre...
That part is a common failure on these engines. Ive changed mine as well. You need to check if all the sensors have been plugged back in properly. Has one come off? The code for thermostat on cylinder head is either disconnected or dead
Find the same one on ebay regardless of colour and you can swap over the cover with your original. The aftermarket gps antenna will work and its usually its the only thing that dies in the sharkfin so the mobile etc still work ok