It may not look like much, but the anti-vibration matting glued to the floorboards of street cars is nasty, evil stuff. It adds weight and is flammable. Once it catches fire it makes a black, acrid smoke and is difficult to put out. So it needs to be removed from any car being turned into a racer. You can scrape it out with a putty knife like you see here, or a wire wheel in a drill also works well. Either way, plan to spend a little time getting rid of it.