Another 18-wheeler truck cab in the proud tradition of Optimus Prime, but in a much much smaller scale -- Overload is an Autobot Micromaster Transport. He turns into blue semi cab that hauls a car carrier. The trailer turns into a "Mach 2" jet fighter that Overload can sit in. He was available in 1989.
The combined form of the Universe Micromaster Aerialbots is Superion, an amalgamation of six robots plus their pack-in accessories that serve as connectors, head, and extremities of the gestalt warrior. While in Japan, the original source of the design ( Sixwing , 1992) was available in a collected set, this combiner needed to be purchased one bot at a time in the 2007 Universe release.