paint

did you sand the primer before laying the base coat? It looks as though the texture is also under the clear from the way the metallic is laying. the only time i have ever seen something spray like that is from an unclean gun or if the clear had an accelerator in it on a very hot day. what brand clear did you use?
i am all for trying to save it but ive been down that road before. even if you get most sanded out you can still pull a burn through and need to re shoot anyway.
As far as tip sizes go i have sprayed clear through a contact cement gun with good results. that should not have effected the clear (its thin) but the primer would be effected if you did not have a big enough tip.
Sand it down, concider the last few coats "extra" and go with the base and clear. you might need a retarder if you are going to spray in hot weather again.