Diagnosis Murder Easter Egg - Elvis!

Actually before he was in the movie "Bye Bye Birdie" Dick Van Dyke played the role on Broadway, for which he won the "Best Supporting Actor" Tony award. However, as he had never received the notification that he was nominated for his performance Van Dyke did not attend the event. He was notified that he had indeed won the following day by telegram. When Carl Reiner filmed the pilot for a new sitcom about a comedy writer, Reiner had cast himself in the leading role. When the pilot was shown the reviewers didn't think that Reiner was believable in the role of the comedy writer. Carl Reiner, who was also the producer of the new sitcom, remembered seeing a character actor on Broadway in "Bye Bye Birdie" and thought he would be perfect for this new part, in what was then a new medium. After their meeting, Van Dyke gave the producers of "Bye Bye Birdie" one month's notice of leaving the show. The Dick Van Dyke Show came from his portrayal on Broadway and the movie of "Bye Bye Birdie", with Dick Van Dyke and a new actress named Ann Margaret wasn't filmed until years later. SirDonQuixote

In the episode Obsession (Part 2), Mark is visiting a radio station, you'll notice that he looks into a room and sees someone, this is none other than Rob Petrie, the character he played on the 1960's program The Dick Van Dyke Show! The company used integrated footage to create this, and t looks quite funky!!!