Here is an example of weight savings through CFRP. The BMW M3 CRT used CFRP for it's hood and stated a 75% reduction in weight vs. steel. Aluminum is about 50% lighter than steel, so CFRP is a further 50% reduction from aluminum.
Rough Example:
Steel Hood: 40lb
Aluminum Hood: 20lb
CFRP Hood: 10lb
Here's a cross section of the CFRP hood
