During a recent preview of its 'earth-friendly' vehicle developments , Nissan also unwrapped this - an Infiniti G37 Hybrid.

Although the automaker has already dabbled with hybrids (the 2008 Nissan Altima Hybrid comes to mind), the G37 demonstrator is the first attempt Nissan's shown at a rear-drive gas-electric vehicle.

We're told the car retains the stock combustion engine, but adds a parallel-hybrid system, not unlike Honda's current "Integrated Motor Assist" system.  The G37 Hybrid's electric motors can help propel the car under hard acceleration, but there is no pure EV mode, even for low-speeds.

Nissan says the G37 Hybrid uses an 'advanced' lithium-ion battery pack (manufactured through its joint-venture with electronics giant NEC), but fails to talk about its specifications. 

Also noticeably missing from the G37's press file is a timetable: We've no idea if or when the G37 Hybrid will come to fruition, but it could help the Infiniti brand survive in tightly-regulated markets.