At 0717hrs Sta. 56 along with Sta. 700, PM17, Station 100 & 200 for the dive team were alerted for a vehicle in Mud Mill Pond. PM17 was first on location reporting 1 vehicle in the water with the drivers door open and plates removed from car. PM17 reported no pts, cancelled the dive team and had units reduce thier responce to a cold one. Brush 56-0 with Boat 56 arived on location. Officer 56-23 (Olechny) astablished Mud Mill Command and reduced the responce to Brush 56 and Rescue 56. Caroline County Sheriff arived and it was determined that the vehicle landed in the DE side of the pond. Box was placed under control 56 units cleared while CC Sheriff awaited DSP. Units Responded: Brush 56 w/boat 56 w/56-23 (Olechny), B-56, Rescue 56 w/FF(Mills), Eng. 702, PM17, Dive 100, 56-31, 56-32, 56-33, CC Sheriff, MSP & DSP.