What about a trailer that can be tucked away flat (collapsed as flat as possible) under the Aptera body, then when needed can be pulled back/ dropped . Perhaps a single wheeled trailer so that the wheel would be right behind the Aptera back wheel so as not to cause much extra wind drag. It can have solar panels on it for extra charge power. The top can be lifted to create space for cargo, or be used as a camper for sleeping. It can perhaps even attach to the back of the Aptera hatchback camping area for a continuous space when used as a camper. The Solar panel top can perhaps be adjusted to face the sun for max power.
The Aptera Forum