I also had exactly the same question as poster. Looking to pick up 2014 S8 with 58K on clock. Youtube - lot of conflicting advice. Are there any recommendations for a vid that you agree on main points? its coming from a main dealer so I wanted to check that the main things had been done before purchase (or ask them to do it). From What I've read so far need to check SH to see if timing belt has been done & gearbox oil. Spark plugs / any coolant leak, turbo supply lines and filter. Silly question - is there a seperate oil filter for the turbos or is this just the one oil filter - so check when this was last replaced.
All electric switches etc. working etc. & make sure tyres are evenly worn / same brand.
Have I missed anything?
Now to find a good Audi Specialist near me (Sandhurst).