Those two are the more specific "RS6" issues, other than those the cars are mainly 10+ years old now so they're getting more generic issues like bushes, hoses etc which are getting old and perishing/cracking so take a very good look underneath the engine bay, around the Gearbox and around the suspension for any DRC leaks.
If you have the ability I'd also take an OBD/VCDS reader if you can just to scan for any fault codes too.