Oil stain on concrete under a car - Nongasimo/Getty Images If you've ever spotted a dark, greasy blotch under the car in your driveway, you know how frustrating it can be. Whether it's a small leak ...

If you're the type that loves to keep a clean car, chances are you've popped the hood and given your engine a thorough scrubbing. From degreasing to gingerly rinsing it with a hose and scrubbing it ...