Abstract: In exemplary implementations of this invention, a foldable vehicle has a foldable chassis. The wheelbase (and thus the overall footprint) of the vehicle can be reduced when parking, and can be extended when driving on the open road. In exemplary implementations the ability to shorten and lengthen the wheelbase is achieved by using two 4-bar linkages, activated by one or more linear actuators positioned in parallel. The dual 4-bar linkage and linear actuator(s) can provide: (i) the ability to maintain full maneuverability in the vehicle's folded and unfolded state; (ii) a fail-safe static system, and (iii) a rigid but transformable chassis.