I've got a 2017 S3 on a 67 plate, but due to a change in work circumstances, I'm racking up quite a lot more mileage on it, its currently at 27k and I estimate i'll be doing 15-17k for work. I know this is going make it depreciate more. If this was you, would you keep the S3 and run it into the ground or change it ASAP for something else before depreciation kills its value because of the mileage? On a run from Wigan to Luton last week I got 43mpg (calculated properly, i.e. not going off the DIS) so it's not bad at all on economy.