Is the sound there at 5 mph? Or just at higher speeds with more wind or wheel movement? Noises are tricky to track down. Maybe the i8 has a part that can move at speed. Perhaps an issue with dust/dirt accumulation? Any variance with rain, or car wash? The brake shield on the F80 was notorious for picking up tiny pebbles resulting in bizarre sounds. How curious that the noise can vary, comes and goes. I have had three i8s - with both different wheel styles - and the noise prevailed! It drives me nuts!!!! I would appreciate hearing what you find out. The result: the noise is still there! It's less noticeable with the winter wheels on, but quite pronounced with the summer wheels (turbine style). Which they finally did a few weeks ago - I've had the car for over two years now! It required them to order and install different wheel bolts. Then, someone on this forum (in a thread on the very same topic) shared a BMW service bulletin that's out on this - at least in the US. I've taken at least three different service guys for a ride, and they all heard it. I've been driving cars with slotted discs for over a decade, and none of them made that noise. Then they declared it must be the slotted brake discs.
When I mentioned it to the dealer, they looked at me like I was crazy. I started to notice it when the summer wheels came on and the windows came down for the first time (I picked up my car in the winter).
