Yes, rubbing compound, but to be honest, I've never found it very successful in getting rid of the line.......Trouble is, the new paint will be a lot softer than the old paint & you'll just end up rubbing off too much of the new paint without getting rid of the line - especially if there's any trace of old polish left on the original paint before you sprayed over it.
It's best to mask off where you really don't want the over-spray to go & with a good aim, try to just blend the spray in naturally........Anyway, try rubbing compound carefully, it might do it. You could do what I've done before, & that's to carefully use a hair-dryer to 'bake' the paint & make it harder..........I will take no responsibility or blame if you end up making a real mess of it by doing any of the above
