Just depends on how far you want to go to lighten any car. I think I remember the old 7 lbs is worth 1 HP

So you strip the unecessary stuff, AC, big radio speaker magnets, ditch the stock exhaust and hanger for soem lite free flowing shit. Get desperate and remove all but one seat belt, no more mirrors, throw out those sissy sun visors and buy some shades...Carbon fiber hood, lighter wheels, go crazy and go with CF fenders, replace the grill with screen door screen, Ditch the glass and go back with plexi-glass, remove the carpet pad and sound deadening materials...You can really go nuts.
Weight is a compromise and if your desperate to get your Camaro/Miata/RX7/Mustang down to roadrace weight start stripping it. Why do that unless you are actually using it in competition I haven't the foggiest clue
Just be happy it rolls and drive it like you stole it!