August 17 is going to be a big day for BMW. Quite frankly, it’s also a big day for the rest of us because the car that we’ve all been waiting years to be unveiled may finally make its debut, at least judging by the look of the teaser photo that Bimmer unveiled in its Facebook page over the weekend. We don’t see much of it, but it is visible enough that we can see the model being a roadster of some sort. It might be a roofless version of the 8 Series. It might even be a new roadster iteration for the i8, possibly one with a Targa roof. We’re not hitching our bets on either model, though, because if this model is what we expect it to be, this is the BMW Z4 Concept.