Hi,
Being (seemingly) the only person from South Africa, I think I should reply to this thread.
Believe it or not, but I visited Echo last week to look at their Kavango caravan (trailer). It is made entirely out of fiberglass, and is as solid as a rock. It should be if you consider the weight (1050kg or 2310 pounds)! All in all I think it is an excellent off road caravan, but it comes at a steep price of about the equivalent of US $ 22000.
It's main rival is the Jurgens Explorer. This trailer can be seen at
http://www.jurgenssafari.co.za/xplorer.htm and is made using aluminum sides. The manufacturing process is therefore similar to many teardrops.
If anyone is interested, send me a pm with your e-mail address, and I will send you a pdf of a recent review of the Kavango.
Also for those interested in tiny off road trailers (smaller than the Echo Kavango), visit the Imagine Trailvan site.
http://www.imagine-trailvan.co.za/
Kind Regards,