Darin, mostlikely, it was a "Test - Mule " from Detroit . Back in the Day, General Motors and Ford and too many times Chrysler would wrap a car in canvas so as to discuise the Sheet metal from the competition . I remember here in Richmond Va. , Chrysler had a couple of Test - Mules here .I think it was around 1961. I had somewhat of an inside as I knew the owners of both a Chevrolet dealership and a Plymouth dealer too. Ed Shaver

see ya on the road folks !