The other problem that the companies had to get over was that right now LEDs can put out only a small amount of light as compared to a filament. With a filament, just change the metal, size, or gas around it and you can get a lot of light so one bulb per housing is enough. Not so with an LED. It takes a lot of individual LEDs to get enough light to drive by. Also, the shape of the light coming off the two is different. Because of that, making a reflector for LEDs was much more difficult and needed computers rather than some guy with a pocket protector and a protractor.