If you are trying to get a deeper gloss then the clear is the answer. If you have dust, bugs or other trash in the enamel, then sanding and shooting the clear may only result in other trash, dust and bugs in the clearcoat. My recommendations if you are just trying to get rid of a few dust specks is the sand with 1500-2000 wet and then buff out. Chances are that without a proper paint booth (not your average garage or home workshop) you will always have some particles or creatures settle into your wet paint. I've been painting everything from aircraft to cars for many years as a hobbyist -- without the benefit of a professional paint booth and I can honestly say I've never had perfect results. Color sanding and buffing is the coverall for our mistakes and lack of expensive gear. Good luck!
