For a quick and cheap solution. Use tooth paste as a polish
1. Apply tooth paste on the light.
2. Rub it a little with a piece of cloth use a little damp cloth.
3. Rub it for 5-10 mins Max.
4. Leave it on for 10-15 mins
5. Remove it with water and a clean dry cloth....
InshaAllah you will end up with light glass like brand new.....Used it my self on 2005 Civic and they became new....
If you don't believe me just give it a try or try it on one of the corners of the light you yourself will be surprised....