I really don't get the point of taking out some of those things. I wouldn't exactly wanna go racing with all my bowling balls riding in back, but I don't think I'd ever go beyond taking out the seats/mats/spare just for a night at the strip either.
Individually they make small weight changes, but altogether they can make the difference between winning and losing. Any advantage you can get (eg, carbon fiber hoods can save 30-40 pounds of weight). So carbon fiber everything from the Hood
, to the rear views, to the lug nuts, to the lights. Remove the spare, and put in run-flats, don't see the point in having fog lights...and so on.