Car scratches?

I just washed my car, and noticed that my car had a bunch of little scratches around the door handle and near the gas cap. The previous owner obviously had a ring, and that did some damage to the clear coat on the car.
After my car was dry, I used this stu from the company called “Kit” it comes in a small yellow bottle labeled “Scratch out”. All I did was pour some on a shammy cloth, swirled into the scratches, and then wiped clean with another cloth. It removes everything except the deep scratches.
The chemical was also recommended for use on yellowed, and aged headlight and tail light fixtures. Using the same process for removing scratches, it made the headlights as clear as the day the car rolled out of the factory.
The bottle is only a few dollars, and can be found at walmart, amazon and other automotive stores.