Oh Boy!!...you are going to get a different answer from everyone on this one. I go strictly by the FSS and had 10,000 miles at the first service. Since the car is new and only has 400 miles on it, I would reset the FSS (twice, to get it back to serve A) and go from there. And yes, use full synthetic Mobil 1 0W-40. It does not break down like the old dinosaur juice. I would be willing to bet that your oil is still so clear that you can barely see it on the dip stick or finger. And mine was still that way at 10,000 miles. Granted, 99% of my driving is interstate...but I'm impressed with the maintenance scheduling.

In the end, it is going to come down to whichever theory you subscribe to.