are you polishing by hand? I know you can get attachments that fit on the end of drills that polish just as well, and go alot faster. Also, the kind of polish you are using makes a big difference too. I have tried many different types on many different surfaces and always get different results. Unfourtunaely, never done a job like ur doing, so let me know how that polish works too!
as far as getting a better polish on it, the best thing you can do is just keep on working at it. It will take time and effort, but the end results will be worth it.
Naz
