BioDieselNow - Renewable biodiesel fuel

I am looking to purchase a 1980s-1990s biodiesel/WVO street legal vehicle, such as VW, Mercedes, Toyota... etc!!!. Need to seat 4 total. Price is flexible depending on condition, age, location etc, BUT not to exceed $6000. I am located in Helena, MT, can travel up to a 500 mile radius to buy. Please...