acrylic can be polished back to clear.... polycarbonate on the other hand will never come all the way back.
there is a kit made by Micromesh to repair aircraft windshields that works good, but all it really is is a set of cloth sandpapers from about 800 to 8000 grit.
I have had good results doing what you did. 400 or 600 to remove scratches, then 1000, 1500 and maybe 2000. follow that with rubbing compound. I like Presta. they make 1000, 1500, 3000... etc. 1500 removes scratches left by 1500 sand paper. I use the 1000 then the 3000. finish with Plexus or Pledge
all this stuff can be had from a real autobody paint store
I would try a small spot to see if you can get all the spiderwebs out. if it works then do a bigger area
edit: oooop... looks like I'm too late. ah well I'll leave the post anyway because the stuff listed works