If the run is in the clear coat only then wrap a paint stir stick with one layer of 1000 - 2000 grit and very carefully "file" it down to level, then polish it out. If the base coat has a run in it and you've cleared over it, then you're gonna have to get down to some serious work. Sand the run out, feather the area to match and reclear the whole thing. That's what I'd do anyway... Good luck
FT