I know, this build went stagnant quick. I can't build more of my car frame until I have the swingarm finished. I have all the parts bearings and such to finish the swingarm and car frame. I am just waiting for a very busy friend to help me out with a little machine work for my swingarm. I've been asking him every couple days and I think he is sick of it, but he is just super busy trying to beat the snow with some house projects. There are a few small things that I've worked on, but don't have any new updates until the swingarm is done. Soon hopefully. I will update I promise. I have a few more questions, but can't really ask them without illustrations.
"For the rear upper mount I would think about a sub-sub-frame to tie the right side to the left side under the seat."
On my DR their is already a piece of tubing that ties the the sides together. If I end up working out the rear mount on the tail subframe then I may have to do what you are saying, but if I keep it on the middle frame tube it will be braced quite well by the factory frame. This is actually part of the reason I want to keep that frame mount set up like it is. I am trying to keep from over stressing the DR frame because I want this sidecar to be easily removable and not change the factor DR stuff. We will see though. New machined parts to come soon hopefully.