As you probably know, scratches show up more clearly on a black car than on any other colour; every scratch, no matter how small, seems to be magnified. There are two different types of scratches--a clear-coat scratch (sometimes referred to as "etching") and a deep scratch that goes through one or more layers of paint. We are dealing with removing shallow scratches, since removing deep scratches involves an entirely different process.
Apply a small amount of Scratch-X (approximately 28.4gr) to approximately a 6 in. X 6 in. area where the scratch is.
Using circular motions with your foam pad, rub the Scratch-X into the paint, using a bit of elbow grease, until the Scratch-X seems to disappear.
Wipe the area gently with a damp microfiber cloth and then add more Scratch-X, again rubbing it in a circular motion, using a bit of pressure until the product once again seems to vanish. Repeat this process one more time, rubbing in a circular motion until the Scratch-X appears to disappear.
Wash the car with a mild liquid soap and dry with a microfiber cloth.
Apply a dual-action cleaner polish, allow to dry and buff, using a clean microfiber cloth.
Apply a good high-tech wax, following the manufacturer's instructions (some high-tech waxes need to dry and others should be buffed off wet), and buff with a clean microfiber cloth.
Don't be afraid to use a little elbow grease when applying Scratch-X. The clear coat on your car is harder than the paint under it and it takes a little effort to rub out clear-coat scratches.