Here's an idea I used on my old '87 back in the day...
What you need is a bottle of Testors Silver model paint and a model brush. Cost about $2.00 at most. Remove the cover and lamp (it might be hot) Carefully paint the plastic behind the lamp and surounding area, but make sure you DO NOT allow the paint to touch the metal clips of the lamp socket (it has metal in it and will short out the socket (which is baad, very baaaad). Wait a few hours (overnight is better) then put it all back together. Your light will be brighter now because you've increased the reflectivity of the fixture. There are newer types of "metalizer" paint for use with airbrushes that might allow you to change the character of the light as well ie gold = yellower tone of light or brass=redder tone of light if you go this route make sure you use a rubber masking material to protect the socket clips and leave a small unpainted "rim" around them. Might do this mod again myself in the next few days I'll try to post some pics to show what I mean Aviator