There's a discussion on the AZL forum about a new GS4 model. Rob A has said if they get 50 preorders with a deposit than the engine could be made. I personally would love to see this happen and this is a in demand engine. I've got my request in for engines so if you want one give Rob K at z track a message to tell him you want one or ten yourself and we can all have a new model with all the latest features. It would be a completely new design. So far the daylight, black scheme and American Freedom Train have been discussed for potential paint schemes.