Understand that the Buff Magic products is a mild compound. It do s not have any protective agent in it. The purpose of that product, or any product like it, is to remove oxidation - period. Sealing the surface after removing the oxidation is left to another product.
The Meguiars product is a combination polish and wax. It is used for less oxidized surfaces.
When I used the Buff Magic product, I followed it up with a one step product like the Meguiars product. After that, I used a straight carnuba wax. In my case, it was a three step project.
What it comes down to is...
1. How oxidized is the surface?
2. How clean and close to perfect are you willing to put in the time to get it there?
I had the time, and decided to make it better than new.
How you decide to do yours is totally up to you.
It is a personal thing. It's not a contest. :wink: