
1) Criminals transport 2) One way to stir 3) Paddy wagon 4) Police van 5) Police vehicle 6) Special kind of vehicle 7) Special vehicle 8) Unpopular vehicle, slang
Found on
https://www.crosswordclues.com/clue/black-maria
[horse] Black Maria (1923–1932) was an American Thoroughbred racing filly who earned national Champion honors three times. Bred in Kentucky by William R. Coe, she was sired by Black Toney, the great foundation stallion of Idle Hour Stock Farm. Her dam was Bird Loose, a daughter of the French stallion Sardanapale, a two-time Leading sire i...
Found on
http://en.wikipedia.org/wiki/Black_Maria_(horse)

This studio was built next to the Edison laboratories in 1893 for the purpose of making film strips for the kinetoscope. Rudimentary in form and structure the studio was so called because of the exterior coating of the building. `Black Maria` was a slang expression for `Police Wagons` which were black in color. The studio was covered, for the most ...
Found on
http://www.allmovie.com/glossary/term/black+maria

Black Maria is slang for a prison van or police car.
Found on
http://www.probertencyclopaedia.com/browse/ZB.HTM
No exact match found.