Advice for buyers
What should I look for in a used Audi A6 saloon?
There's very little to worry about, provided the car has been serviced on time by people who know what they're doing and who use decent parts.
A full service history - either at Audi dealers or specialist Audi independents - is absolutely essential. Without it, you're taking the risk of landing yourself with some expensive repairs in the future, as well as saddling yourself with a car that will be significantly less desirable when you decide to resell it.