Nice!
However, I'm guessing a mocked-up photo (albeit a good one) as the grill is neither like an A5s nor an S5s - think I last saw the hexagonal-mesh grill on the previous generation RS6 although I could be wrong.
The wheels look suspiciously BMW to me as well, but again it may be an Audi design I'm not familiar with.
I think Audi should stick with the brushed aluminium A pillars like the current A4 cabrio though - it really sets it apart from the rest of the current A4 range.