Mariah was a converted London taxi owned by Darius Pike. She stayed in the garage and was under almost constant maintenance by Darius.
In 1963, Mariah was owned by Darius' great-grandfather, William Pike. She was later modified to run on alternative technology and given a cybernetic brain.
William's cab was never identified as Mariah but as it appeared identical to her and the official K9 site states that she was a converted ancient cab, it is likely it was.
Darius and Starkey drove in Mariah on their way to Dauntless Prison.
When Drake tried to frame K9, he had K9's duplicate severely damage Mariah at night. This made Darius furious, but when a CCPC grabbed Jorjie he sided with K9.
One night, Darius slept inside Mariah. In a dream induced by the Bodach, he was surrounded by Clowns inside the car. He begged Mariah to open the door but she said she couldn't do that; their destination was the circus.
When Darius was banished from the Gryffen Manor, he drove off in Mariah. When the Anubian Geb tried to hypnotise him, Mariah knocked him out by opening her door in his face.
Darius used Mariah to drive Birdie to a safe place.
When Darius was affected by news of the Last Precinct, Mariah comforted him.
Darius was sleeping inside Mariah when Thorne came to him.
Mariah could communicate in a feminine voice, operate under a voice recognition system and move without a driver. She appreciated Darius clearing out junk food wrappers from the back seat.