No, but I know plenty of people who have. No one ever said they picked up that much time from 50 lbs. All the old timers I know say 100lbs = .1 seconds. So 400lbs to trim four tenths.
I'll set my Dart up with stock sheet metal and run it down the strip. Then I'll swap to fiberglass front end and trunk lid and run it again. According to you, I should shave off four or five seconds with that much weight off the car. That would be awesome!
