We are sanding to 320- Then using red scuff pads- I'll try hitting the areas with 400- 600 and see what happens- Afraid that I went a bit too far (deep) with the 320 and maybe the scratches are from that- also we have not been wet sanding- which again could have attributed to the scratches as the primer dust might be balling up and clogginthe paper briefly - not too sure. We'll try the 400 then 600 tonight and see what we get.