Answer by taking a quote from the following article:

Ian Matthias Bavitz (born June 5, 1976), better known by his stage name Aesop Rock, is an American hip hop recording artist and producer residing in Portland, Oregon. He was at the forefront of the new wave of underground and alternative hip hop acts that emerged during the late 1990s and early 2000s. He was signed to El-P's Definitive Jux label until it went on hiatus in 2010. betterPropaganda ranked him at number 19 at the Top 100 Artists of the Decade.

In February 2005, Aesop Rock released a new EP, Fast Cars, Danger, Fire and Knives. The first pressing of the EP included an 88-page booklet with lyrics from every release from Float until this EP (the lyric booklet is titled The Living Human Curiosity Sideshow); later pressings of the album come without the booklet, but with an additional bonus track, "Facemelter". In addition, a limited number of albums were available direct from Def Jux with Aesop Rock's graffiti tag on them. In response to demands from his fans, Rock did less production on the EP: three songs are produced by Blockhead, three produced by Aesop, and one by Rob Sonic. During this time he was asked to join The Weathermen to replace Vast Aire.  Aesop Rock was commissioned to create a 45-minute instrumental track for the Nike+iPod running system, entitled All Day. It was released in February 2007. Distributed via the iTunes Music Store and featuring his wife Allyson Baker on guitar and scratches from DJ Big Wiz, Aesop has described the release as "something that evolved enough that the sound was constantly fresh and attractive, as though the runner were moving through a set of differing cities or landscapes."  All Day was followed in August of the same year by Bavitz's fifth full-length album, None Shall Pass released in 2007. The album also contained original artwork by Jeremy Fish. About Jeremy Fish, Aesop Rock said: "Man that guy is my hero. We have a friend in common who hit me up a while back saying that this guy Jeremy Fish had an opportunity to pitch a cartoon to Disney and wanted me to be involved in the music side. I flipped out cuz I was also a fan of his, and owned some of his work." Aesop Rock also teamed up with Jeremy Fish again in a project called Ghosts of the Barbary Coast. Aesop Rock made a song called "Tomorrow Morning", to go along with a slideshow of drawings that Jeremy Fish drew. This was displayed in San Francisco, but was also made available for download online. None Shall Pass had positive reviews from critics and fans, applauding Aesop for his change in sound.

What is significant about the Fast Cars EP?
In February 2005, Aesop Rock released a new EP, Fast Cars, Danger, Fire and Knives.