I actually have two "thru sleeves" in the cross member just inside the inner rocker on both sides and I have a "pull " wire running thru the right frame connector so I can pull my battery cable from the trunk up without having it exposed. The plan is to mount fuel and brake cables to the sides of the frame connectors since they present such a nice tall flat surface.
I'll post pics when we get around to that. There have been many discussions about that sort of thing. I even have pull wire inside both rear frame rails since I had the trunk floor out. There will be minimal wire exposed in this car when it is done.
My 30 years of remodeling work has paid off here as I am always thinking about how to conceal wire and pipe!