I have been wondering what new character to replace Sam. I have said before Chip would be could in the next movie, but what about Spike and his dad sparkplug.? I often wondered if Sam was portraying Spike, but never got that evidence. If that was the case the next movie could have a older Sam/Spike and his son Daniel, like the classic G1 movie. Any how I just want TF4 to come as soon as possible no matter the main human character! As long as Hot Rod is finally in the movie. Spike would be the right choice for a fresh new face to replace Sam.