As I was pulling apart a 1990 SE, I took out that center trim that goes around the radio and climate control. In the back of it I saw a bar with a green light in it. What is it used for?

 

It's a bulb light "diffuser" thingy, it reflects the light into the bose display, but if you've gotten rid of your bose then it's useless, it just shined light onto cds as I put them into my cd player, but I removed it