Here I have started to do my side reference plate, for this I did not need to create any more grids using the spline tool but I had to just pull the vertexes. But before that because the surface of the front reference plate is still flat I had to pull the vertexes out or even adjust some distorted lines that later may will be a nuisance to me.

You can see that here I have changed the flow of the the lines by curving it more by pulling the vertexes, and I did that for all the surfaces that I have created.