Hi .
The paintwork is very good it's obviously been detailed... Only marks are little stone chips lower front spoiler..
No marks inside benefits of low miles I suppose .. one previous elderly owner who looked after it .
I get the same answer of friends of friends or are fitters... John oil is oil mate.. if you feel better and think it's of benefits just buy reasonably cheaper full synthetic and change it more often... So, I suppose there is no correct answer but like to listen from advice to way things up. I'm sure the dealer will say bring it in many times as you like .£££. lol.