Actually, the Concept Cloud Car and Snowspeeder were designed by McQuarrie, but the bike was a Joe Johnston design. Now, if Hasbro wanted to do Joe Johnston Concept line, we could get some very cool figures.
McQuarrie also did a nice X-wing/Tie painting for A New Hope, the x-wing, in my opinion, is different enough to warrent a toy, but still iconic enough that non-hardcore collectors might like it.