second modified , armored van spotted near des moines , iowa alongside the one that hillary clinton travels in .
visually identical black vehicles ' biggest difference is the color of their new york license plates .
one is a chevy and the other a gmc but they are mechanically identical and one was seen using secret service-fitted red and blue lights .
van dubbed ` scooby ' in homage to the scooby-doo cartoon show brought clinton to iowa from her new york house .
` scooby-two ' made its debut in norwalk , iowa on wednesday outside a fruit processing plant where clinton made a scripted appearance .