You can now buy it as a t-shirt on the Redbubble site here! [link]UPDATE 02:
Rate this design to become a t-shirt here: [link]
Rating is now closed
.UPDATE 01: Featured on Equestria Daily Drawfriend 813? No way! No way! No way? [link]Whoever sent this in, thank you!
T-shirt design entry for the WeLoveFine shirt design contest that's going on, inspired by one of my favorite Sonic shirts I have. And yes, Rainbow Dash is drawn in SA style.
Will put up a link to the entry when the voting period starts.
See second update.