With the astonishing advances in electrical motors, capacitors and batteries lately its entirely possible for a car to in certain conditions to use dynamic braking to return home with more energy than when it left for a days commute, with computer aided drive by wire in commuter carlanes, percentages of downgrades or even the combined charging of solar panels while the cars waits through the work day its entirely possible, practical and researchable.
I think i just heard a lot of Arabs groan.
I think you are right. The technological developments are startling.