When it comes to trailers there are multiple options:
Buy a trailer on Craigslist or a auto trader site (but do your homework on the load capacity)
Buy a professionally built car hauler or custom built trailer (this is what I did).
Buy a trailer specifically built for Tiny Houses.
The one option I didn’t list is using an old RV trailer. This is a dangerous solution that some have attempted but RV trailers simply aren’t designed to handle the weight of a Tiny House. Even if you buy one you’d have to modify it heavily and potentially replace it’s axles. By the time you’d finish you might as well purchase a custom trailer.
I purchased a car hauler trailer from Pro-Ride Trailers in Louisiana and love the trailer but wish I’d had saved a bit more and bought a Tumbleweed or Tiny Home Builders Trailer. Instead I had to spend time and a good bit of money custom modifying my trailer to support the overhanging weight.
No option is wrong, but the below options are the best ones for Tiny Home builders.