The maintenance map is well-charted. Plan for the timing chain as the car ages (it will be due, and parts aren't cheap), treat the motor and dogbone mounts as consumables worth upgrading, and replace the clutch slave cylinder (a known weak link) at the same time as the clutch, since it can't be reached without pulling the transmission.
Watch-items: timing chain, mounts, slave cylinder
Audi TT RS (8J) · mechanical