I follow the law and register my vehicles in my domicile state. Registering out-of-state to avoid paying taxes is illegal. But I'm not going to rat anybody out for doing so— our great nation was founded
on the principle of tax evasion, going all the way back to the Boston Tea Party.
Plus there are loopholes to register out-of-state and still be legal, such as forming a corporation incorporated in a specific state that has low corporate taxes, and making the vehicle or trailer a corporate asset; which is a trick yachtsmen use to register hideously expensive yachts and avoid paying excise taxes. By registering in the corporation's name, you're registering in-state for the corporation
, regardless of where you personally happen to live.