Some of the most effective scratch repair kits include the Turtle Wax Premium Grade Scratch Repair Kit and Meguiar's ScratchX 2.0 Swirl Remover, according to online reviews at Autozone. Prices on these products as of June 2015 range from around $12 to $19.
The Turtle Wax Scratch Repair Kit comes with everything a car owner needs to fill in and blend scratches away. To use, simply wash the damaged area of the automobile, apply the color using a color coded restoration pad and apply a clear coat finish. See product for full instructions.
The Meguiar's scratch removal system can be applied with a polisher or by hand. This formula is abrasive-free so it won't scratch paint, and enhances color and gloss.