Maintain that new car smell, and protect your expensive seats from odors, stains, and wear. That's the purpose of quality, waterproof seat covers. And what is the number one reason your car interior no longer has that glorious new car smell. Don't point to your passengers who may be wearing perfume or a deodorant you don't like, or your kids who refuse to wash their lucky socks because with them they've managed to win 8 soccer games in a row. Oh no, the number one cause of your seat covers smelling a little bit rancid is due to good old-fashioned sweat. You see, sweat, which is primarily composed of water, salt, and other chemicals is pretty much odorless until it gets mixed with the bacteria of your body.