Fiberglass 1/4's and hood?

I'm building my car for open track days at road coarses and autocrosses. I'm not to conserned where they place me as far as classes go. But I would like good times. Do you or anyone know how practical the front fenders are on the street, rain? Lightening a car improves everything. Acceleration, braking and cornering. The fiber glass fenders and hood would remove weight off the nose of the car and help balance it it out more in cornering? I'm just wondering if it's worth the trade off,,,,,,, if any? I don't know?