what about an episode where Mika is just playing himself? In the video for grace kelly, at 0:12, the window in the back suspiciously looks like a TARDIS... and the noise also sounds like the TARDIS landing... so my idea of an episode would be:
The doctor and amy decide to surprise rory (in my dream world, Rory is a crazy Mika fanboy) and take him n the tardis to crash the video shoot for Grace Kelly. They meet Mika, who gets curious about the Tardis, and who wants to shoot his video on the inside, but the doctor is VERY against this idea. So Mika, being the mischeivous guy he is, sneaks into the tardis when the doctor isnt looking, and accidentally transports himself somewhere, where he uses a communicator inside the tardis to follow the doctors directions to come back (and somewhere along the road, he needs to sing for his life). Then he comes back, and is so happy that he invites the doctor and his companions to be a part of the video, but as they are filming, the tardis leaves. The doctor then explains that time can ve rewritten, but you cant play with it too much and the ending shot could be the new "extended version" of grace kelly with the tardis noise XD