CA has gotten much more aggressive in clamping down on people who could be considered residents of the state but are not. Every RVer who spends six months or more in the state should be careful (see: http://www.nbcbayarea.com/news/local/CHP-Cracking-Down-on-Out-of-State-License-Plates-266159301.html).
The CHP has a program called "CHEATERS" with a Webesite where your neighbor can report you if they believe you haven't properly registered your plates in CA.
If you're legally a resident of a state other than CA but try to purchase a vehicle in CA, they will try to nab sales tax on that vehicle (so you'd be paying your own state sales tax, if your state has them, PLUS CA's steep (7.5% - 10%!! depending on where you're making a purchase).
Many RVers who spend 6 or more months out of the year in CA have no idea how close they're skating to the thin ice that covers CA residency.
