The pictures are an Amt Dukes of Hazzard charger mounted on a wood board with a styrofoam ramp then the whole thing was covered with bathroom caulking then painted to look like muddy brown earth. The car is held up with a bent coat hanger held by the caulk, When it dried I mounted the car on the hanger then covered the hanger with florist moss to hide it. I also used moss on parts of the painted caulk for brush and weeds,I also used cut paint brush bristles painted dark green for patches of grass.
http://photobucket.com/albums/y141/rudiment5967/123098/