All I know is that the Solstice uses reflectors in their headlights, and the Sky has what is called "Projector beams"
EDIT:
this is what I found out on the internet about "Projector beam headlights".
Projector Headlight
When driving, what you can’t see and all those that can’t see you can be fatal and dangerous. That’s the main reason why almost all vehicles come with various sets of vehicle lights. The pair of light that’s typically installed in front of the vehicle is called headlights. These are lamps designed to illuminate the road ahead while driving in poorly lit areas or during periods of low visibility, particularly at night. Headlights are one of the earliest safety features mounted in the vehicle.
Most headlights today are electrically operated and are required to emit a low or a high beam. High beam headlights give off beam that’s straight ahead to maximize seeing distance, but they usually send out too much glare and cause back dazzle brought by the reflection from rain, fog and snow. Low beams, on the other hand, controls the light that goes upward and reroute most of their illumination downward and either rightward or leftward. This is aimed to deliver safe and excellent forward visibility without too much glare or backdazzle.
Headlights come in many types. Xenon headlights, HID headlights, Euro lights, halogen headlamps and projector headlights are among others. Replacing your existing vehicle headlights with projector headlights is among the great ways to enhance the car’s façade. Not only do they look good, projector headlights also give improved night visibility because of the brighter beam they produce and the wavelength of colors they give off. Projector headlights are offered in chrome, blue, black, red and other colors and are crafted to look so sleek that they are often mistaken as though they were customized.
To give you a clear view, projector headlights is a type of headlight that gives out a stronger beam to light a more focused area with very accurate light dispersion and less scatter loss. Its design works like a slide projector and it allows you to see what you need to see sooner and more vividly. In projector headlights, a filament is positioned at one focus of an elliptical and a condenser lens is placed in front of the lamp. At the image plane, just between the lens and the reflector, a shade can be found and the projection at the top edge of this shade is the one that gives the low-beam cutoff.
Purchasing the right projector headlight is very significant whether you’re planning to customize your truck, SUV or car or you want to enhance its driving safety. For a monochromatic and more attractive appearance, there are also taillights that are made to compliment your projector headlights. Should you want to customize your vehicle lights or you just need a replacement headlight, the best choice is projector headlights. Projector headlights are perfect for your restyling or customization job. Aside from their slick style, projector headlights are also easy to install. So if you wish for a car that really stands out from the crowd, update its style especially its front fascia using finely-designed projector headlights.