TOY FAIR 2002:
Li'l Prime's robot mode has an intricate double-layered chestplate structure. The only thing to which I can think of comparing it would be Transmetal Ravage / Tigatron, and even they aren't exactly right. Swing down the outermost level of Prime's chestplate, and you can see his sculpted Matrix. Now pull away his entire chestplate assembly, and the Super Prime head is gazing out at you....
The animated clip of Prime's trailer transforming via radio-signal was.... scary? Okay, trailer-into-base wasn't too threatening. It was very reminiscent of the spring-loaded transforming trailers of Laser Optimus / Black Convoy: the whole trailer violently heaves itself upright and then completely topples over, leaving bits and pieces of it behind as freestanding platforms.
But when the base mode transforms into robot lower-body mode..... well, gah, it really looks like it sort of pulls itself together and stands up under its own power. In very strong defiance of where you'd think its center of gravity was, and just basically quite unlike what you'd normally think of a toy ever doing on its own. Eeeeee.
The explainer said that the trailer could interpret signals from the cab in such a way that it would always transform into the required mode. The radio signal is said to function out to a distance of 5 feet.
A special note on Prime's Minicon partner, Sparkplug:
For tiny, tiny toys (remember, 2"), these Minicons look like they'll have really astounding transformations. It honestly took me a few tries to work out all of Sparky's little catches and swivels. Basically:
Copyright 2002 Altered States Magazine.