does the scratch look like a) a 'pastier' shade of your cars colour or b) white?
if a, itll rub out with a good medium compound like meguiars ulimate compound (g3 is so watered down that it will take alot more elbow grease for it to have an affect)
if b, then its down to primer, which can be fixed, either respray the whole door, or, cut back the clear coat, touch up the scratch with repair kit, cut that back to blend then re-lacquer, but that doesnt always work and its time consuming
cleaning products will only go so far, but not as far into paint damage