Its hard to match a polish to a paint surface problem without seeing it; one size does not fit all.
Diagnosis is the key; not guesswork; always use the least abrasive product / foam pad combination before ‘stepping-up’ to something more aggressive. The most important first step in the process of paint surface detailing is diagnosing the paint surface; density of clear coat (hard or soft) or single stage paint, surface condition; severity of the scratches and the paint thickness available will dictate the choice and abrasiveness of polish / compound for correction or renovation level required or indeed possible.
Try Menzerna's new polish - Power Finish (PO203S) - (M) this is a one-step scratch remover polish that will remove 2500 grit, cut 3.0-gloss 3.5, is made for the OEM market as a quick way to polish out light flaws and amplify the paint’s gloss.
This will remove moderate to mild swirls, water spots, and light scratches. then it burnishes the paint to an ultra high gloss, like you’d expect from Nano Polish (for black or dark coloured paint surfaces use as part of a duel level foam pad / polish system PO 85 RD 3.01 Super Intensive Polish) 1500 RPM - primed LC Orange / Green (mid range, high density foam (60 PPI) medium abrasive cutting action) or a White primed (softer less dense foam (70 PPI) with a light abrasive cutting action)