Looks like a giant M3 to me



From the article:
BMW's designers will probably take the evolutionary route with the 5-Series (G30) set to come out in the second half of next year which means the range-topping M5 won't be out sooner than late 2017 / early 2018. RM Design decided to share his vision of the high-performance mid-size Bavarian sedan which for the first time in its history will likely receive an optional xDrive all-wheel drive system.

2 pictures and full article

.