The purple polish is a great product. don't throw it away. Use it to maintain your polish, you will find it will give a deeper, more clear shine that nuvite, after the initial polish is done.
I loved my polished -4, the only thing I would urge you to consider is some paint, or wrap on the top of the wing, the reflection while flying can be brutal. I thought it was worth it. but my wife hated it.