What Ryland said is true. Almost without a doubt the hood has the look of carbon fiber only. They either fake it with dyed fiberglass weave or they lay one lamina of carbon fiber fabric for the look and back it up with layers of
glass fiber reinforced polymer.
S-Glass (a good glass fiber) has a density of 2.49g/cm^3, and a modulus of 86GPa where T300 (a lower end carbon fiber) has a density of 1.76g/cm^3 and and modulus of 230GPa. Just by switching to carbon fibers the hood gains several times the strength to weight ratio (Tensile properties are technically worse, but a hood is unlikely to fail in tension, it just needs to hold up to the wind under bending). Then there's the resin, which is a great percentage of the weight in a cheap layup and a small percentage of the weight in a high tech, vacuum bagged, oven cured, prepreg setup.
Note the need to have a vacuum in your oven and also notice only formula one, bikes, tennis rackets, and the newest airplanes are switching to carbon fiber instead of aluminum?
To point out one more thing, a crumple point for safety in a collision has to be designed whether or not the hood is steel or fiber reinforced polymer. If you buy a crappy aftermarket aluminum or steel hood you're probably just as bad off as buying the fiberglass one, in my opinion.