The tarnishing is supposedly caused by the "Truck Wash" cleaners used at roadside car washes. A previous owner of my car must have gone every weekend 'cos mine were particularly bad and really let the car down - its always bugged me since the day I bought the car.
My headlights were looking tired too so I splashed out on some G3, a machine polisher and various different grades of 75mm polishing pads and set about sorting both issues out.
I've got to say the results of the high gloss window trims in particular are spectacular.
It took a while and it was a messy job - I'm sure a pro could do it in half the time and with a lot less mess but its been worth the effort.
I gave them a good clean first up then masked up along the paintwork as the paint is likely to be thinner on the edges and I didn't want to polish through it with the G3.
Using plenty of water I started with a harder compounding polishing pad then finished off with a softer 3M finishing pad.
Finally I gave them all a coat of wax to give some protection.
See the results for yourself - they're back to their original deep glossy finish and the car looks great.
Before;


Its a messy job!

Results;


