BTW. Just throwing this out should someone search and find this thread.
In some states, registering your RTV (or any other ATV/UTV) is required.
If you go to register it, in some states the VIN# fails. All other vehicles from cars to ATV's have 17-digit VIN's. For some reason Kubota only put in 16 so the software kicks it out as in invalid VIN. It's been a few years, but I worked with the state and had them get around it. I'm not 100% sure, but I believe I had them add another zero to the "10" section to get around it. We put it there as that seems to be a stagnant, somewhat irrelevant portion of the VIN.