Starting to sound like "Woodstock with Circular Saws". :/
I reverse my position on recommending doing it in the Home Depot parking lot. Bad idea. Hopefully it doesn't get out of control, in terms of size, and end up with the same problem as the Summer RTR. Maybe some advance planning can avoid that (dispersed pods, share vehicles to congregate discreetly for a workshop, joint meal, van-raising, etc). Small groups with periodic hub get-togethers. An organizational method used successfully in lots of other places, programs.
On the other hand, it will probably turn out to be like lots of other stuff -- high initial interest, but small attendance.
Final thought for the moment:
I'd love to exchange ideas, brainstorm, assist in stages of construction, etc. If applicable, be on the receiving end of some of that. However, the thought of my van/truck getting the miraculous transformation visited upon the sad Christmas tree from the end of "A Charlie Brown Christmas" gives me serious pause. Too much of a control freak for that. Anyone can rush and throw shit in a box with enthusiasm. I'd want it to come to fruition more slowly so that I could understand it all and agree to it all along the way. Plus, it's a bit unrealistic to expect 10 empty vans to show up, and then go from zero-to-60 on build-out in less than two weeks. Some help is better than no help, and that's the way I'm approaching it, if I'm lucky enough to approach it at all.
Just my 2 cents and feedback for the organizers.
Vagabound