Congrats on your great car and welcome to the forum.
Regarding oil, I have never needed to add oil between changes, but I have an '04 and that may be a difference. Dunno. However, one tip I learned is to keep the oil level about .5 quart below full, especially if you are tracking it. I concluded this on my own after 'an experience', and discussed it with a driver in Porsche Club Racing and he said he did the same thing.
Have fun!
