I painted the bonnet, and some other details on my old nissan patrol with silverflakes.
It requires some work...
1. spray the clear-coat with flakes, let it dry.
2. go over the painted area with fine sandpaper and wet sand it. Do good work here, and make sure its smooth.
3. spray again with clear-coat (no flakes)
4. If the result is good now you are finish with the paitning, and can start polish the car. If its not good repeat step 2&3.
If you use a poor flake-fabric the flakes can either sink or float in the clear-coat, and you will get an uneven layer of flakes. Test the flakes, and trye spray something just to test it (like an old patrol)
Tried to upload pics, it failed. So i used a norwegian pic uploader site: