When it's a trailer and a lemon....
While federal Magnuson-Moss protections may be available as leverage to get warranty assistance, many states exclude Trailers from their Motor Vehicle definitions for purposes of Lemon Laws. California, for example, includes drivetrain/chassis portion of motorhomes, but not trailers...
All the regular licensing and motor vehicle regulations apply, including traffic regs, but you may not qualify for replacement or re-purchase or even binding arbitration relief if your trailer fails to live up to your expectations and their warranty...
Your mileage may vary...
John McG