I assume the runs you are referring to are the one's on your
pedal car?
If so, sand the complete car (600 grit DA, then 1000 grit wet). Get all the shiny spots out of it and make sure your runs are 'flat'.
Spot in the runs, while being sure you don't get metallic all over the car...in other words, keep your pressure low, and even mask off each area individually. Leave your masked area larger than what you need for your blend area.
If you have one of those stripes you can mask up against, that would even be better.
Now blend your candy. The better you blend in your base metallic, the easier it is to do the candy.
Now reclear the complete pedal car.
You'll find 'reclearing' over the candy a second time will really help cut back some of the orange peel and give it even more of a nice gloss.