The clever thing to do would be to give this toy a trailer hitch that makes it reverse-compatible with a previous Optimus Prime's trailer, like say G1 OP's trailer. Obviously adding a wheeled plastic box would significantly add to the cost of the toy, but giving a simple hitch would improve the play value and allow collectors to simply attach another trailer to it.

And it's not unheard of for them to sneak in a feature like this -- Reveal the Shield G2 Laser Optimus Prime is able to connect with the original 1995 G2 Optimus Prime toy's trailer.
