MAS 1
From Tardis Wiki, the free Doctor Who reference
MAS 1 was a car once owned by the Tremas Master and the Master's Auton. He remarked it as "not as silly as Bessie that the Doctor used to drive". (GAME: Destiny of the Doctors, HOMEVID: Destiny of the Doctors)
Also a twitter poll happened and the doctor who fans on twitter voted for their favourite name and the name Beatrice won. So her fandom chosen name is now Beatrice.