Mate Bartha, says the car is all about. According to the designer, inspiration for the rendering came from ancient chariots, and everything else fell into place after that.
The front end has been designed in such a way that it hints to the horses used by the Greek armies, adorned with lines which point to the warrior's helmets. The back is the chariot itself, while the side of the car gives us an insight into the body armor of the soldiers.
Now, all of the above is the official story, which can be found on Bartha's website. We on the other hand, although are willing to admit we kinda see where the author is going with this (if you look closely at the car, you'll see it pretty much matches all those ancient things), and see a totally different thing.
The BMW Chariot Roadster is perhaps the best-looking BMW design study which will never be produced. We don't know what Bartha envisioned to be fitted under the hood of the car, and frankly we don't care. The car looks amazing and we kinda feel sorry we'll never get to see it, probably not even in concept form.