Weight savings

Where would you cut weight in you car if it were for race only and didn't have the money to spend on fiberglass?

My Demon already has a fiberglass hood, and no passenger seat. The rear seat is still there but needs to come out, and a firewall installed.
I've heard of people cutting pieces out of their doors that saved a bunch. Not sure what they chopped out. Pictures would be good.

Looking for sugestions.