When the car is painted during the manufacturing process, the metal gets coated thrice, starting with a primer coat followed by a colour coat and finally ending with a clear coat.
Analyse how bad the scratch is. If you can see still see some paint, the scratch is not very deep and can be taken care of very easily. If you see the metal, all three coats have been removed due to the scratch and the entire panel needs to be painted again.
Wash the scratched area carefully using a rag dipped in soapy water and then let it dry. Once the scratched area is completely dry, apply some shoe polish into it. Use black polish if the car’s colour is light and use white polish if the car’s colour is dark. Use just the right amount of shoe polish because using too much polish will do no good.
Gently sand the scratched area to sand away the shoe polish around the scratch using the 2000-grit sand paper. Mix a few drops of liquid dishwasher soap to cold water and dip the sandpaper in it. At angle of 60°, sand the scratch carefully. Do the dipping and sanding step continuously for around five minutes. After that, let the area dry.
Once dry, the scratched area is ready to be coated with the auto rubbing compound. After applying the auto rubbing compound, scour the scratched area using a terry cloth. This will restore shine and repair work you have done will not look out of place.
Finally, to remove any left off auto rubbing compound, scour the scratched area once again, this time using a chamois cloth.