Hi Alex and welcome to the forum
Most modern cars do not need any rust protection unless you are going to hang on to the car for a long time, say seven to ten years. I personally had done nothing as I only intend to hold onto my Ecosport for a maximium of three to four years, and trade -in, while it is still worth some money.
I used to use wax impregnation, and also tar based underseal on previous cars to prevent corrosion underneath. Its really only the underneath and sub frames to worry about as most modern cars have good bodywork, assuming no rust trap areas, and are covered by a bodywork guarantee.
According to Ford’s website, comes with a three-year paint surface warranty, while the perforation guarantee, for rust generated from the inside out, is for 12 years. The first cover period is shorter as damage to the paint occurs naturally, due to stone chips and other external factors.
Not to say there can never be bodywork faults on any car, here is an example of an angry Ford owner with a known rust trap area on a Focus....https://www.carbuyer.co.uk/news/1519...er-rusty-focus