This concept supercar can be modified either as a plug-in hybrid or a fuel cell-powered vehicle. We're most excited about the prospect of a plug-in hybrid, which Mercedes claims can run on pure electric power for 18 miles at 75 mph before switching into hybrid mode. And of course, the car goes ultra-fast--155 mph with a cruise control system that can navigate curves under 25 mph.

This the first plug-in hybrid from Porsche, and it doesn't disappoint. The 918 Spyder concept goes 0 to 60 mph in 3.2 seconds, gets 78 miles per gallon, and can supposedly go 16 miles on pure electric charge. The car weighs a relatively light 3,285 lbs (including batteries) thanks to carbon-reinforced plastic body panels and an aluminum and magnesium chassis. Oh yeah, and it's really, really good-looking, too. Porsche says that there is a fair chance the Spyder will go into production, so stay tuned.

Ferrari's hybrid electric supercar is bright green--literally. The car, which is Ferrari's first attempt at a hybrid, is based on the 599 GTB Fiorano. It offers the usual impressive Ferrari stats--200 mph, zero to 60 in 3.5 seconds, and 125 mph in 10.5 seconds--but without the familiar engine roar. Ferrari expects the technology to hit showrooms in three to five years.

This concept hybrid version of the Lotus Evora goes from 0 to 60 in under four seconds and has a range of 300 miles. The car also boasts 408 horsepower and 590 pound-feet of torque. And unlike many of the other supercars featured here, the Evora sounds like a good old fashioned speed demon--it uses HALOsonic Internal and External Electronic Sound Synthesis systems to give it the familiar engine noises we know and love.

The hybrid version of Audi's A8 has, according to the automaker, "power like a big V6, fuel economy like a modest four-cylinder unit". We can't disagree. The A8 takes 7.6 seconds to rev up from 0 to 62 mph, has a top speed of 146 mph, and gets 38 mpg (compared to the traditional A8's 34 mpg). This one is still a concept, but we're guessing it will be pretty pricey.

It's not quite as sexy as Porsche's 918 Spyder, but the Cayenne is impressive in its own right. Unlike most of the cars featured here, the Cayenne SUV isn't a concept--it's being released in Europe on May 8. The Cayenne boasts 380 horsepower, 34.4 mpg, a 288 volt nickel metal-hydride battery, and it can cruise up to 97 mph on electric power alone--albeit only for 2.8 miles. Not as impressive as some of the other cars here, but again, it's not a concept. Expect to pay $86,599 for this model.

The hybrid version of BMW's 5 series offers a a 53-horsepower electric motor, eight-speed automatic transmission, and a straight-six gasoline engine with TwinPower Turbo technology. No word on when this one might hit showroom, but BMW assures us that the car's "combustion engine and the electric motor, are able to offer significantly lower fuel consumption and emission ratings at higher speeds."

This beautiful hunk of carbon fiber is six and a half feet wide and measures 192 inches in length. The stats: 4 electric engines that deliver 800 hp, a peak torque of 1500 NM, zero to 60 in 2.7 seconds and--wait for it--a top speed of 234 miles per hour. The all-electric Quant is powered by both a conventional battery and a pyrite film covering that act like a solar cell. No word on when the Quant will ship, but it will feature either a metal-air battery or a Redox Flow Cell. And yes, we know this one isn't a hybrid, but it's just too hot to ignore.

Citroen Survolt concept was one of the most buzzed-about cars in the show. The automaker is usually known for tiny hatchbacks, and the Survolt falls along those lines--slated for limited production, it's a tiny, tiny electric supercar, at just 12.5 feet long and not even four-feet high.