In my state (Utah) the DMV has decided that if the vehicle (HMMWV or any) is capable of passing the state inspection program (which is strict on safety equipment) it can be registered as "Road Worthy." Now, what this means is there are several upgrades that will need to be done. A good example is bumpers, unless the HMMWV has air lift bumpers it will need an upgrade. It is a farely simple requirement in Utah, meet state inspection requirements and your good to go. As far as "Not Road Worthy" from GP, that can apply to 95% of the vehicles they sell. Lights not working, wipers inop., flat tires, broken glass, missing parts, etc. the list can go on and on. So, the "Not Road Worthy" and "Off Highway Use Only" stamp are a in my opinion a CYA tactic. So in effect, buy 25 year old stuff, declare exemption from DOT, FMSS, and EPA and go play with your toy as you wish.