i was hoping someone could help me out... i am needing to find some material similair to what is inside the interior components that lets the light shine through evenly (in my case the green lights). need roughly a 7"x3" piece so i'd probably be looking at a roll of the film. any help or suggestions is greatly appreciated.

 

White paper. If you want a pattern or words, print them on it with your inkjet. If you want an even color over it, buy taillight repair tape at a parts store. That's how I did my ENG (red) & ALT (yellow) lights, but I didn't put any effort into making them look decent. Functional was good enough for me.