Overheat is a ship created by tiny people called Chromies which looks like a 1954 Mercury Monterey. The back half of the ship is piloted through a wild world. We can glimpse this world through the back window. 

The Chromies' belief in us is what summons us to their ship. We produce energy they use through pressing buttons. They cannot see us, but we can see them when we push a button. This energy is transformed by mechanical beings deep inside the engine. They get melted but they are fine.

They store the energy in eggs which provides sustenance and joy for them in their world.  

The front of the ship exists in the Almalgam space. The paint has gotten pulled off by the Waveweaver.