Nu Finish Scratch Remover, and as mentioned, Meguiare's Plastic polish, are very good for haze and very light swirls and scratches. For more pronounce scratches, try 800, 1200, and 1800 or 2000grits sand paper. Start with the 800 working your way up to 1800 (2000) grit. Sand paper is to be used with water only, never dry, make sure your surface is always wet.