These are actually a sub-category of bolt-together models. 

Harbor Freight has a 35”x55” model 2948-9VGA with sides that would work well topped with one of our “Oasis II” tents.

We are currently evaluating a small footprint trailer frame kit for building a smaller, “micro” version of our Explorer Box. This frame is also looking like a great starting point for building a sport utility style kayak / bike trailer at ~25% the cost of one a Dooit or Rack and Roll trailer. Drop us an email and we’ll send you an update when further information is available.