PlastX is a waste, as someone mentioned above, it's too specific of a product. I have a bottle I tried, blah. I'm a big fan of using whatever I can pick off the shelf, so I have plenty of Ultimate Compound and Swirl Remover that I use on headlights. Works great and I don't have to wait for shipping.
I do however have bottles of 105/205 that I use most of the time. But, when I first started doing headlights, I used my regular 5.5" pads and UC/SR.
I have a YouTube video when I purchased a bunch of stuff. I will be posting another one soon using the combo above.