Has anybody ever used one of the headlight restore kits to try and clear up the old, scratched t-tops?

 

Poly-carbonate polishes pretty easily. I've never used the headlight restoration kits but, I have polished them.

 

I've redone two sets of them, one I went the "headlight polishing" route using a DA and sand paper and got really good results. The second set was too far gone so I sanded them down and painted them body color. To answer your question though, yes a headlight polishing kit will work, but there might not be enough supplies in a single kit to get the job done.

 

You can make the surface shiny. You can't polish out the hairline cracks that form inside the poly-carbonate. When the outer surface is REALLY bad, it's like they're pitted and rough. If you smooth all that out, with say... like... uh... maybe start with 80 grit, then 220, 320, 400, 600, 800, 1000, 1200, 1500, 2000 and then finish up with a high quality plastic cleaner and polish. When you get to that eventuality, you'll see all the crazing INSIDE the plastic.

Ok, I'm exaggerating a hair, 80 grit is probably excessive, 220 might be too aggressive. 320 is well within the scope of reality to remove the pitting in the last set I had. Guess the point I'm making is if they haven't been cared for properly, and preserved, there's probably not anything that you're going to correct beyond what will clean up with a careful hand polishing with plastic cleaner/polish. Short of replacing the plastic, which in most cases isn't practical either, you're not going to to accomplish much with any chance of long term results. It's a waste of time and money.

Have you found glass? Consider accepting Glass T-tops as your roof's savior, you can enjoy the benefits of eternal longevity. </Mormon>

 

They are Lexamar !