Any of the above will work, machine polish is the best, I have used MAG Headlight Restorer and it worked well. :thumbs:
http://www.ebay.co.uk/itm/MAG-Headlight-Restorer-Polish-Cleans-Glass-Plastic-Lamp-Covers-Made-In-USA-/170744815298?pt=UK_Car_Accessories_Car_Care_Cleaning&hash=item27c12f1ec2