New York: BMW has unveiled a pair of concept cars, one a hybrid and one electric, made of light-weight carbon fibre and a see-through glass exterior.

The cars, unveiled on Wednesday, are expected to go into production within the next two to three years.

The carbon fibre in the i3 city car and i8 sports car significantly reduces the weight of the vehicle and the size of its frame, giving designers more flexibility and creating more interior space for passengers, said Richard Kim, who designed the exteriors of both vehicles.

The material, used in the aerospace sector and also for high-end bicycles, is valued for its strength-to-weight ratio. Its uses are expanding, however, and engineers are designing everything from camping equipment to pool cues.

For the German automaker, it allowed for more glass where there is traditionally metal, Kim said. The doors of both vehicles are mostly made of glass, along with much of their roofs and tail ends.

BMW said the car offers "superb safety in the event of a collision."

The final product may not appear as dramatic, but will have the same feel as the concept cars, Kim said.

"You may not see as much glass, but you will be able to see the light coming through," Kim said at a sneak peak event Wednesday in New York. The cars officially debut next week at the Los Angeles auto show.

The i3 is expected to go into production in 2013, with production of the i8 following a year later. The cost of the car has yet to be determined, though carbon fibre is not cheap.

The four-door i3 is designed for urban driving, with its wheels pushed out to the corners of the frame for stability.

It has coach-style doors, with rear and front doors swinging open at the centre of the vehicle.

The added stability of carbon fibre allowed designers to eliminate the support pillar traditionally found between the front and back doors, which will make it making it easier to enter and exit the vehicle, Kim said.