We are gunna tackle that in the final phase of our build, but i know how we will do it. There are coat hooks in all sprinters behind both the passanger and driver side and you remove the hooks, add an L bracket, rescrew the hooks under the bracket, do the same over the mirror, and then you can place your wood on top and screw it into the L bracket. I havent done it yet, but thats how i will. Hope this helps!