Polishing headlamp glass

Anything that does the same with car paint. T-cut, etc. Just harder work by hand.

Just the usual cleaning techniques.

there are special compounds such as displex. I would not use any metal/paint polishes as they may re-act with the plastic and make things worse.

I have referred to the aviation industry usage. This has to be good stuff there acrylic windscreens and windows are expensive to replace.

Here are some good reads they may help to understand the process.

I've used various metal polishes on various plastics without any ill effect. What polish were you thinking about and what plastic?

FWIW I keep Solvol Autosol (chrome cleaner) in this workshop and is my first choice to polish near anything that needs an abrasive.

FWIW, I'd find it odd a car maker using a plastic which could be damaged by contact with another product commonly used on car paint.