Luckily the series can currently be found streaming for free at Adult Swim's official website (which you can find here). The series can also be found on the official Adult Swim app as well with no login required.
But this will only be the English dub of the series as the Japanese language release with English subtitles has been delayed until November out of respect for Adult Swim and Toonami's partners in Japan.
Adult Swim describes FLCL Progressive as such:
"FLCL Progressive tells the story of 14-year-old Hidomi, her classmate Ide, and two otherworldly beings, “Jinyu” and “Haruha Raharu,” who are determined to unlock their hidden potential. Mixed up in this is an all-powerful force known as “ATOMSK,” a gorgeous vintage car… and a certain Vespa Scooter."
The English dub cast for the series includes Kari Wahlgren as Haruha Raharu, Allegra Clark as Jinyu, Xanthe Hunyh as Hidomi, Robbie Daymond as Ide, Jon Allen as Mori, Yuri Lowenthal as Marco, Christine Marie Cabanos as Aiko, Julie Ann Taylor as Hinae, Jason Griffith as Marurao, J. David Brimmer as Eye Patch, and Steve Kramer as Tonkichi.
The staff for the series includes directors Kazuto Arai, Toshihisa Kaiya, Yuki Ogawa, Yoshihide Ibata, Kei Suezawa, and Hiroshi Ikehata with Katsuyuki Motohiro serving as Chief Director for Production I.G. Hideto Iwai will write the script for the series, Yoshiyuki Sadamoto and Chikashi Kubota are handling character design, Taeko Hamauzu will serve as editor, R.O.N. is composing the music for the series, Noriko Arisawa is overseeing the color design, and famous band from the first series the pillows are returning for the series' opening theme "spiky seeds."
FLCL, pronounced in English as “Fooly Cooly,” was written by Yoji Enokido, directed by Kazuya Tsurumaki, and produced by Gainax, Production IG, and King Records and released in Japan from 2000-2001. It came to the United States as part of the Adult Swim block in 2003 it was frequently re-aired from 2003-2014. The coming-of-age story focused on the 12-year-old boy Naota Nandaba who become bored with his life in a working-class town. He gets more excitement than he bargained for when the alien Haruko Haruhara bursts into his life on her moped, trailing chaos in her wake.