Found it! In Hemmings again, too. Here's a part of the article:
once graced the Proving Ground: a 40-foot-long replica of a Studebaker President Four Season Roadster.The 2.5:1 scale replica of the attractive new 1931 President was created as a prop for a nine-minute promotional film called Wild Flowers. The job of creating the model was given to Paul Auman, the head of Studebaker's experimental body shop in the spring of 1930, in advance of the model's introduction. According to The Studebaker National Museum...Over a Century on Wheels by Andrew Beckman, the museum's archivist, the body panels, made of white pine, were shaped in the Studebaker factory in South Bend and assembled at the Proving Ground. Firestone produced the 10-foot-diameter tires for the model, making certain that its name was prominent on the sidewalls, and the spokes of the wire wheels were created from electrical conduit.
Painted in two shades of green, the giant President, 14 feet tall, weighing 5 1/2 tons and riding on a 325-inch wheelbase, commanded a grassy bluff just to the west of the main gate. So that no one would miss the point, a silhouette of a man in a suit was stationed at the front bumper, leaning on a sign that read, "This Man is 6 Feet Tall." The display generated its fair share of publicity for the company; typical was an article in the December 1930 issue of Popular Mechanics that carried the headline, ''Studebaker Builds World's Largest Auto.'' An object of endless fascination, it must have been a can't-miss photo opportunity for residents of the area and tourists passing through.
The passage of time, the ravages of the harsh Indiana winters and vandalism by souvenir hunters finally got the better of the big wooden President. In the spring of 1936, workers removed the hubcaps and two of the mammoth tires, doused the model in an accelerant, and set a lighted torch to it. Within 30 minutes, the car had been reduced to ashes. The pine trees were planted the following year.
The appeal of the giant car had captured imaginations in South Bend, though, so much so that another giant, this time of the 1934 Land Cruiser, was created for that year's Chicago World's Fair. But that's another story for another time.
(This article originally appeared in the July, 2010 issue of Hemmings Motor News.)