Years ago my windshield cracked and had to be replace and unfortunately it seems this aftermarket rubber isn't worth crap! Any suggestions on what I can do to save it/restore it???

Thanks in advance

 

Try some high gloss Armorall.

Won't last long but it should improve it.

 

You could try using 0000 steel wool. I have used it before on rubber trim with success, but not on the trim you posted. If you try this, make sure you use some painters tape on the paint so it does not get scratched.

 

Might be a bit late, but I'd recommend a good all purpose cleaner with a stiff brush and then a good dressing. I think it might help but it's hard to say without seeing it in person or trying stuff.