Sanding final coat

Ok, thank you all

I'm with littletimmy!  I use about 3000 grit. Fortunately these days, such extremely fine sandpaper is widely available, from hobby shops and even auto parts stores.  2000 is about the finest you want to touch up a final coat with. Gloss or flat clearcoats will cover up the frosty look from those grits, not the abrasions you get with anything more abrasive.

Did you use a rattle can or airbrush? Sounds to me you sprayed too close and heavy - which I suspect you have tape lines on the hull.

Mars

I have some of the gray scotchbrite used by a local autobody shop for sanding between coats of the same color.

I would think the Scotchbrite is a bit "TOO" abrasive for this. I have never worked with it so I"m not sure but,I feel it would leave unwanted scratches/ gouge's in your paint. 

Maybe try sandpaper. A fine grit 2000 to 6000 grit .

Just my 2 cent's worth..... other's with more knowledge will be able to help more than me.