I'm sure this is far too late for this year but in case it is not. My hubz and I are long-time van sluts with many years in the desert camping. Our van is dark blue so becomes a total furnace in the sun. Here are our tried and true methods:
* Reflectix from Home Depot for all
windows (silver bubble wrap that comes in a roll - search the brand on HD). Cut it to just fit or *slightly* larger than the inside of each window. We've found most tapes don't hold up in the desert heat but duct tape (bring a whole roll) will do in a pinch. We have used elastic string in the past to fasten them in but eventually that wore out. We now have slide tabs screwed in around the windows that we are very happy with but requires some pre-camping installation. Reflectix is best we've found for keep the heat out over curtains, cloth, foil, etc. Because it is not only reflective material but also insulated. (This is also a bonus to keep heat in when we snow-camp)
* For the windshield, buy an insulated reflective sunshade is easiest.
Depending how lazy we feel about set up and how mobile we want to be once we set up camp, we have two methods that keep us cool sleeping well into mid-day especially if there is even the smallest breeze.
1- Van Burrito
Super easy. Buy a giant snow camo tarp from an online army surplus type place. It should be significantly larger than your van. Wrap it over the van and secure it to the undercarriage most of the way around. Where your sliding door is leave excess room and stake to the ground so you can get in and out. This is also a good place to store your cooler. This has the advantage of presenting a very small footprint to the wind and minimizes tearing during storms. This has the disadvantage of making more of an effort if you want to leave camp and drive (tho not a problem at BM). And there is no place to sit outside under the shade, only inside the van which is totally fine sometimes especially if you are with a larger camp that has group sitting shade.
2 - Quonset Hut
A bit more prep but and supplies but less expensive than a carport (which is totally legit as well for shade). Use the same snow camo plus pvc poles, rebar, etc. and build yourself one. I would write up a bunch of directions but someone else already has with instructional pictures even. http://www.wps.com/J/BM/PVC-Quonset-Hut-assembly/