This might be a simple question but what`s the difference between LARS and Proto LARS? Also is there a track section from either of these that will unload and load double stack well cars with the same type of containers that I first put on them? I can`t get it to work like I want using MIN. If I have 48`s on top and 40`s on bottom when it reloads the train it put all 40`s and then switches to 48`s when it runs out of 40`s.