Joined automobiles are disclosed. Two separate joinable automobiles, each with its own control system, powertrain, and interior space, can be joined by means of built-in retractable coupling systems, providing a single joined automobile with a contiguous inner space, two powertrains which can be used singly or together, and two control systems. The coupling systems can be used by putting the automobiles in proximity to each other and engaging them, and/or disengaging them for separate use.