hi,
Actually, as I went into making a sample, I realized there is a much better approach to all this, simply by scrolling the texture itself. This means, not prefab, not management of objects positionning, so it's very simple to implement.
Please find attached a sample. you'll notice that to achieve several "instance" of your background, simply adjust the scaling of both the mesh and the material texture scale, in that example, I have twice the background showed on the mesh.
Bye,
Jean