sanding scratches in plastic molding?

hey guys, ok so I decided to take on refinishing my molding -a pillars-door handles- etc.   I sanded them down with 100 grit, and finished them with SEM Color Coat.  But after about 4 coats I let them dry and now I have fairly course scratching, its not a smooth finish. Any ideas on what to do?  Should I wet sand now that they are finished?  They are pretty course scratches though so I didn't know if that will work??? How bout primer or something? Thanks for the ideas!

anybody???

You needed to go to a finer grit if you were going strait to color. I usually go 100, primer, 320, primer, 600, color, light 600 if needed, color again if needed, clearcoat, 1500, polish. I don't have more grits than that right now, but it seems to work pretty well. If you are going to go from sand to color, then go to 600, this will give it a smooth finish and will still give the paint bite. As for right now, sand the current paint with 220 - 400 maybe wet if you want and then go to 600 for finish to make sure there are no scratches then two or three more coats of color and it should look pretty good.