Apparently there really is a sequel to Life on Mars, the crackpot time-travel romp involving a comatose copper who finds himself in 1973. It's called Ashes to Ashes (geddit?) and features the character of DI Gene Hunt, the macho boss of Sam Tyler in the original series.
Gene is now eight years older and posted to London, where he's joined by another time-travelling sidekick. Except this time, she's female. And some kind of Cracker-style shrink. I think we'd all agree that to encounter one chronologically challenged cop in your career is unfortunate. To share a station with another is just downright careless.
The result, I suspect, will be utter Confusion. Probably played by the Electric Light Orchestra.
I suggest a cameo appearance by Ken Livingstone, who in 1981 had just installed himself as firebrand left-wing leader of the old Greater London Council. Gene would no doubt see Red Ken as commie stooge and sparks would surely fly.