[camhenlin]

In Toyota's hybrid synergy drive, the electric motor system is inputting to the same transmission as the ICE engine, and is an integral part of the casing. You can see a cutaway of it here to get an idea of what it looks like in practice: https://en.wikipedia.org/wiki/Hybrid_vehicle_drivetrain#/med... What you're describing is indeed how the E-Four system works for the rear wheels on the AWD versions of the Prius