plastic whitening tip,
 

I read about using peroxide and oxy clean to whiten plastic parts. here are the interior under dash lenses from my 72 gt ragtop, I used one to start because I wanted a before and after comparison.

http://i62.tinypic.com/op7m69.jpg

I sanded the insides of the lenses with 180 grit then 220 then 400.
Mixed 1 cup hydrogen peroxide with 1/2 tsp oxyclean and put in the plastic. I put it in a glass jar covered in plastic wrap and left it in the sun to bleach for three days then repeated with a fresh batch of solution.

I thought they came out pretty good. Thought I would pass it along.
Regards, Pete.

OxiClean =
sodium carbonate (washing soda)
sodium carbonate peroxyhydrate (hydrogen peroxide)
ethoxylated alcohol (alcohol surfactant)

Nice job!