I have this article from 'Instructables' - which may be known to many here. I enjoyed it very much and it gives a good perspective of a 'How to' job.
Personally the foam and permanence is a bit of issue in my mind, no allowance for future modifications, and/or especially interior wiring for appliances, etc. I'd do it different, but the essentials are good, and I got something from it.
They did an ok job in not compacting the fiberglass insulation, but it still looks fairly compacted. A foam-board insulation would probably be a better use in this situation since it doesn't compact like fiberglass.
The vapor barrier should go over everything, including the foam-in-place insulation and the metal structure, not just the batt/board insulation. Unless the structure is completely welded there will be lots of places for moisture to get through if you don't.
Unless the side panels are vented, any water that gets in there will be a rust hazard. In an 80, make sure your drains work and don't get plugged. Preferably they would have a small air gap between the sheet metal on the outside of the van and the insulation to allow what water does condense to run down the sheet metal and drain.
You will still need to find a way to vent the moisture from the van when you are sleeping in it. There should be much less condensation on the walls (at least if you do the step below this), but there will still be quite a bit if it is really cold out. They do mention this in the comments.
The metal structure/bracing that attaches to the outside skin and passes through the insulation is going to reduce the effectiveness of their insulation to less than 1/2 of the nominal R-value that they installed.* A 1/2" foam or board insulation over the top of the metal structure (but still below the vapor barrier) would probably double the effective R-value of the van. I would guess that if they had just kept the silver bubble wrap insulation continuous and wrapped it around the structure it would probably as effective as all that other insulation without covering the exposed metal that they have in their final picture. You would also have much more space to run wires for whatever you want to do in the interior. They mention a cedar interior which will have some of the same effect, but since the bubble wrap is so thin, why not both?
Make sure whatever duct tape you use works as a vapor barrier. The cheap duct tape from HD/Lowe's probably won't cut it. Their Tuck Tape looks like it would work fine (I haven't checked though).
*I base this on typical construction framing standards: A 2x6 metal stud wall with studs at 16" on center and completely filled with R-19 insulation only has an effective R-value of 7.1, so the metal studs effectively reduce the insulation by over 60%. The structure in their van appears to be more than every 16", so I would expect it to reduce the effectiveness at least as much. Adding a continuous R-6.5 insulation that doesn't stop at the framing takes the overall R-value to over 13.
