Well, the thread is 12x1.25 and the standard is a 60mm tapered seat for most aftermarket wheels and this is true for the bbs wheels or the base model wheels. So I got a bit curious to find out why aftermarket lugs don't work with the bbs wheels. Why I've found is that the diameter of the hole is a bit different, smaller, and thus the lug seat is a bit smaller on the factory nuts. Aftermarket versions being a bit wider. What this does is it doesn't allow the aftermarket lug to sit squarely on the wheel seat. The pressure is applied over a smaller area vs. the larger area area of the OEM nuts. Now, I've never really seen anyone speak of a failure due to this but it is possible that there could be due to the decreased contact area.
I also caught a blurb about McGuard nuts being the way to go as they are a match for the diameter of the hole. Personally, I use the Muteki nuts and they seem to seat fine on both the BBS and my aftermarket wheels.