EZ Spreader, an Amish farm supply company, makes a fiberglass bed wagon with superior weather handling.  The entire 20"x40" bed bottom is one formed piece of fiberglass, with no wood in the bed. Red painted hardwood racks then slide into the holders, or plastic red racks are also available.  The undercarriage is also in red. 

Wagons with red racks over white are generally available in a week.  Other color choices on the wood racks may be available; e-mail or call for availability and shipping time, as it may be several weeks for custom painting. 

We agree that God never made fiberglass trees, but fibrous-glass reinforced epoxy plastic makes a great wagon!  Own a "glass over four wheels" for less than the cost of one alloy wheel on a Chevrolet Corvette- not included!