Random orbital sander/buffer...same/same... abrasive pad for sanding, foam buffing pad for polishing.
Do no more than about 1 metre sq at a time and finish each section off with a quality microfibre hand polishing cloth as you go. A good r/o machine used correctly will give a finish completely devoid of swirls.
You will be a bit nervous to start with but once you get the hang of it you can do a whole car in no time...

Most auto spares shops stock buffing pads....eg Auto One who also sell AutoGlym products.

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