Find out what is hiding in the dark on August 17th at Pebble Beach. pic.twitter.com/1SZp8w4VXR— BMW (@BMW) July 28, 2017
The only other details we get about the vehicle are from the teaser sketch included in the tweet. The car is quite obviously a droptop of sorts, and it appears to have cowls behind the seats, indicating it could be a two-seat speedster. The lengthy nose also suggests this is a front-engined car. BMW does have its Z4 successor in development, and we have yet to see any kind of preview of that car aside from spy shots. However, we think the car suggested by this drawing is too long to be the relatively compact, Toyota-based BMW.
The size would be fitting for a speedster version of BMW's upcoming 8 Series flagship coupe. BMW is also getting close to releasing the big two-door, as evidenced by its recent coupe concept, and near-production-ready prototypes we've seen in spy photos. Now the two-seat layout might seem to contradict this, but for a concept, it would be easy to add the extra bodywork and cowl to cover up the area seats would have filled. If it reaches production, a convertible 8 Series probably would retain its rear seats, similar to the 6 Series cabriolet. We look forward to seeing the fully revealed car in a couple of weeks.