Hi Art.
I'm registered in South Dakota and I just registered my new 2016 promaster 3500 there. I couldn't believe it...
The registration ended up being labeled a car. The price? $96. And when my plates arrived, there was a letter enclosed saying I had been overcharged and would be receiving a $18 credit.
I use these people here for my address stuff. They'll scan the front cover of all my mail, then I can request them to open and scan the contents, or recycle it, or shred it, or forward it anywhere. They have their own app that makes it all simple. And they'll register your vehicle for you without you having to show up for $35. They just did mine.
http://www.americas-mailbox.com/