I installed mine just like Allen did.
Seeing some
light is a difficult issue to avoid since these doors have bend in them. Mine shows some
light along the bottom but is doesn't leak rain there so I'm okay with it. If that were on the top or sides (especially the hinge side when driving in the rain) that would be a problem.
Adjustments would need to be made by perhaps adding a thin layer of rubber to the door, where it meets the seal, to fill the gap.