It’s not easy following the bouncing ball of the General Motors plug-in crossover SUV. The vehicle was originally conceived as a Saturn Vue in 2007, became an unnamed Buick model in August 2009, and two weeks later was a technology in search of a vehicle.

The plug-in hybrid Vue was originally planned for 2010, but now all bets are off. GM maintains its commitment to a plug-in crossover SUV, but the vehicle platform, brand, price, and production date are all yet to be determined—although 2011 is bandied about as a possible date. “I can tell you that I won’t lose one day in terms of customers being able to walk into dealerships and actually purchase a plug-in,” GM Vice Chairman Tom Stephens told Automotive News in July 2009. “My job is to get it out there and get it right the first time but then get it cost-effective so that we can do a huge number.”

The plug-in Vue was going to utilize a modified version of GM’s two-mode hybrid system, plug-in technology, and an advanced lithium ion battery pack. The system was being engineered to achieve significant increases in fuel economy, as much as twice that of any current conventional hybrid vehicle. Rick Wagoner, former chairman and CEO of GM, acknowledged that there are steep technical issues to overcome—battery technology being the most volatile.

The advantages of a plug-in hybrid-electric vehicle over a non-plug-in hybrid-electric vehicle are its extended electric-only propulsion, additional battery capacity, and its ability to be recharged from an external electrical outlet, meaning common household current. The Saturn Vue Line plug-in hybrid was expected to offer electric-only propulsion for more than 10 miles. To propel the vehicle at higher speeds, electric-only mode would switch to either a combination of engine and electric power together, or engine power by itself. The powertrain is composed of two permanent magnet motors and GM’s 3.6-liter V6 gasoline engine with direct injection.

GM’s two-mode hybrid system will be modified for use with plug-in technology. The system maintains two separate driving modes—one for city, the other for highway. The key to the whole system lies in the transmission, which is geared to maximize efficiency while still granting solid performance, whether for accelerating on the highway, treading over rough terrain, or towing a trailer.

During operation, the lithium ion energy storage is be designed to utilize the electric motors and regenerative braking. And of course, the battery can be replenished by simply plugging into a 110-volt outlet.

The combination of truck-like capabilities and ground-breaking reductions in fuel use could mean a big success for the plug-in, in whatever form it takes. That is, if and when it is reincarnated into another life form. Time will tell.