here is what worked for me on my 15...

1.i clay barred the lights.

2.i wet/dry sanded with 1200 using fairy liquid and water as lube(amost as much fairy as water)...nice smooth even strokes ,dont fixate on a certain area..

3.i then used g3 compund and my rotary buffer...(set to moderate speed and when compound is spread you can bring speed up to increase cutting)...i also misted the buffer pad in water before applying compound to it.

4.i then used autoglym super resin polish

5.finished off with two layers of wax...they were like brand new...i applied wax every time i waxed the resst of the car and they never faded...