The 1996 Pininfarina Eta Beta was the result of a research project undertaken on behalf of the Italian National Research Council and aimed at the creation of a prototype with the modulated interior, equipped with a low-emissions dual-power plant, constructed with entirely recyclable light materials and ideally suited for urban use and medium-range out-of-city travel.
It was a radical city car concept using an aluminum space frame with aluminum doors, bonnet, and tailgate. Other body panels were plastic, keeping weight to a minimum. The Eta Beta had a hybrid drivetrain. The front wheels were powered by Fiat 1.1 liter engine, while the electric motors drove the rear. The luggage compartment could be enlarged by pulling the rear section of the car out by 15cm
Source: Pininfarina