Jack Safro ,who now owns Jack Safro Toyota in Brookfield, Wisconsin came up with the idea of the Trekker. He approached Winnebago, and they in collaboration with Toyota, approved of the concept, and started on the design options. Several vehicles were produced for crash testing. Once approved, production began.
The Trekker was produced in 1981 and 1982, and a limited amount were also produced in 1983. The Trekkers were produced in both 4x4 and 4x2 models. The total production of the Trekker was around 1200. Most were shipped out west, with Colorado being the biggest receiver. Limited amounts were sent east. Roughly 20 of these Trekkers were also sold to Saudi Arabia. (from http://www.toyotaoffroad.com/Articles/Toyota/Trekker/Trekker.htm )
although , we'll probably never know the exact origins of the trekker , as sadly , Jack Safro passed away in 2009 .. and most employees and staff whom , were either involved , or worked at dealerships at that time , have now either moved on or retired ...