Started framing up the carryall today. Cut boards to 44" so the overall width stays inside the tire tracks. Drilled all the holes but will have to wait until Tuesday to bolt it all down as the box of 1/2" galvanized bolts didn't make it in bag with the other stuff I got. Wasn't going to make an extra trip for them. I called them and they will put back for me at the customer service counter.
I'm going to run it as is for while before deciding on sides and other add ons.