Well
Coming from someone who has done the MOTO van thing and has also worked for a very high end upfitter of vans, (Becker automotive)
The advice that I’d have to offer is this:
Make sure the damn gas for the bikes can is sealed well, secured well, and near the rear door at all times. In an ideal world, you’d drain the gas out of the tank into said cam after riding, but in all reality, shove a bolt or something in the vent hose. they tend to smell like a garage no matter what one does usually, it’s kinda unavoidable. However, having run a bike with methanol at one point in time, I learned the extreme of how nasty fumes can get.. another thing is make sure the bikes are secured well enough so that they can’t fall over, because that does happen sometimes.
the rear door makes a good spot for consumable spray items, with mechanical spray prevention methods when not intending on spraying them (such as a cap)
A good bulkhead is a must, a place to sleep behind the driver and passenger seat is always nice, LED under cabinet strip lighting in the back, around the headliner/roof is a god send, especially if you manage to 3 way the means of turning it off and on to both doors.
don’t rip the headliner out of it. Keep some side panel insulation in the back to cut down road noise. Carpet the bulkhead. Bolt a tool box down, make some shelf’s for the bulkhead or cabinets if your inclined to do so, even make a sub woofer box off the bottom of it under the bench seat behind drivers seat if you go that way.
you will most likely spend some LONG days and late nights in the thing if your traveling to races. Make it as enjoyable/comfortable as you can justify. Don’t skimp on a nice sound system, and head unit with a backup camera Inuit. The rear view mirror is pretty much useless with a bulkhead. A hideously annoying car alarm is also very important. Tiny all the windows it does have dark as hell, as you don’t want anyone seeing inside it for any reason due to the dead giveaway of its contents if they do see. Well. Maybe not the ENTIRE windshield..
on the van I had we did 5% on the driver and passenger. 2 layers of 5% on the rear windows as it was a 15 passenger van, and a brow on the windshield. Never got messed with for it.
lastly. Refrain from putting 96,000 stickers that scream there’s motorcycles in here on it. It’s a dead giveaway for people with bad intent to go see what’s with all them stickers. Sadly most vans are pretty easily broken into, so the more precautions such as big fuck off locks, or other means of preventing physical forced entry/stealing of the van it’s self, the better.