The headlights felt before Rau and were slightly dull and blotchy. After the treatment you were really nice and smooth and the stains were gone.
Deeper scratches and Co. can not be "just" out polishing. You have to be pre-treated with sandpaper this already.
Comparison pictures of my Astra G headlights are included here.
Greetings
EDIT: So after a year to see the lights unfortunately again as before. So you have one of these tedious work every year !!