[91STT]

Typically polishes will remove a very fine layer of paint. Waxes would not. If a wax is advertised as being able to remove oxidation than it is essentially a polish even if it says wax on the bottle. I haven't used Black Magic before so I don't know if it is a wax or a polish. Check the bottle to see if it says it can remove oxidation. It is possible that the other cars that you used this product on has a clearcoat finish. In this case you would not see it on the rag you use to remove the haze. I am assuming that you have a 1G red 3S in which case you have a single stage finish therefore no clearcoat over the red paint.
It is recommended that polishing be kept to a minimum since it does wear down the finish. Frequency of waxing is really up to you. Waxing usually does not hurt the finish. I usually wax my car when I see that the wax starts to lose it ability to bead water. Which can be 2 weeks or a month or more, depending how much I drive it and how long I leave the carcover off.