Passage: During the December 2014 press conference announcing the start of filming, Aston Martin and Eon unveiled the new DB10 as the official car for the film. The DB10 was designed in collaboration between Aston Martin and the filmmakers, with only 10 being produced especially for Spectre as a celebration of the 50th anniversary of the company's association with the franchise. Only eight of those 10 were used for the film, however; the remaining two were used for promotional work. After modifying the Jaguar C-X75 for the film, Williams F1 carried the 007 logo on their cars at the 2015 Mexican Grand Prix, with the team playing host to the cast and crew ahead of the Mexican premiere of the film.To promote the film, the film's marketers continued the trend established during Skyfall's production of releasing still images of clapperboards and video blogs on Eon's official social media accounts. 17 brands appear in the film through product placement, and many of those, such as Heineken, Bollinger, Omega and Sony—owner of the film's co-distributor Columbia Pictures—did Spectre tie-in advertisements.On 13 March 2015, several members of the cast and crew, including Craig, Whishaw, Wilson and Mendes, as well as previous James Bond actor, Sir Roger Moore, appeared in a sketch written by David Walliams and the Dawson Brothers for Comic Relief's Red Nose Day on BBC One. In the sketch, they film a behind-the-scenes mockumentary on the filming of Spectre. The first teaser trailer for Spectre was released worldwide in March 2015, followed by the theatrical trailer in July and the final trailer in October.

Question: What event caused the DB10s to be created?
celebration of the 50th anniversary of the company's association with the franchise