I'd visit the dealer and let them handle it. I realize the oil viscosity recommended is 0W-30 or 0W-40, but are we sure that's what's used for break-in? With all the oil pumps changed, I'm sure the maintenance department knows what to do and can hook you up in short order.
At 400 miles are you being told to add oil or is your electronic dipstick a segment low? As I'm sure you know, be careful to avoid overfilling if you opt to do this yourself.