Best State Residence for Full-Timers

I sold my home in Colorado in March 2014 and have been full-timing in my AS ever since. Now that I've figured out the basics I'm starting to think long-term, like what is the best state for my official residence to minimize taxes (e.g., AS license plate ownership fees/taxes). I paid around $2500 to Douglas County, Colorado for my first year's license plates and have heard I can dramatically reduce this amount next year by changing my state residents. I plan to keep traveling full-time but am under the impression the government requires I have an official state residence for my drivers license, license plates, taxes. Is this true? My primary consideration is minimizing taxes and license fees. I will have no income for the next couple of years so income tax rates are not a concern.

Would appreciate hearing from others.

Thanks,

Rob