Rust Prevention Advice

Hey Oppo’s. My sister ended up buying a 2012 Mazda 3. It’s alright overall but it has rust starting and she wants the rust to stop before it become a typical Midwest car. These photos show where the rust is. Any advice to stopping the rust where it is short of repainting the whole car? Thank you!!!

The car in question
The car in question
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There are a few spots on the roof like this.
There are a few spots on the roof like this.
Rear driver’s side door edge.
Rear driver’s side door edge.
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Driver’s side rear wheel well
Driver’s side rear wheel well
Passenger side rocker panel.
Passenger side rocker panel.