We decorated our SUV for trunk or treat once, turning it into a graveyard. We used that green indoor/outdoor carpet to cover the floor, adding hills to it. We also used a big piece of cardboard as the backdrop (propped up by the two front seats) and my husband spray painted a spooky house and cloudy night scene on it. Then, we constructed some headstones and coffins out of cardboard. It looked great, and the kids loved it!