The roller "marks" are caused by the roller itself during application of the primer and paint. It is a roller stipple. This can be minimized by using a smooth roller cover, flocked foam, and adding a retarder to the paint to help it flow out. For oil base paint/primer use Penetrol and for water based paint use Flotrol.
Oil base paints naturally dry slower therefor they will be smoother. With the addition of Penetrol oil base paint can flow out to a very smooth finish if applied correctly.
For a true smooth surface you will have to spray the primer and paint. The only way to remove the stipple is to sand smooth and repaint.