I have had 3 Caymans and always had the oil changed annually irrespective of mileage. It comes out looking as good as it went in but having raced motorbikes for 20 years I have lot of mechanical sympathy. It isn't required by Porsche but running for 2 years on the same oil just doesn't sit right with me. On the subject of the grills , I had them fitted to my 981S by the time it came round for extended warranty with no OPC comments. Also, as mentioned in another post the OPC encouraged me to fit them on my GTS when i bought it new and even offered to do it. I think that some OPC's are just a bit more pragmatic than others.
Neil
Neil