REDLINE/WMG

The leader of the Mafia was the pimped out guy in JP's flashback.
Both wore rings, were rich, and had two beautiful women (and I swear they look the same). This may have actually been stated, for all I know and I missed it... there was a lot going on in the movie.
 * It wasn't stated, but the Mafia guy (Inuki) does kind of look like a much older version of the flashback guy.

The Redline Race is actually a coordinated and precise attack on Roboworld
Especially after seeing all of the illegal weaponry that Roboworld had stockpiled, it seems that other governments, ruling bodies etc knew about them and used the race as a method of sabotage/attack effectively destroying their most dangerous military capabilities. Plus the Redline Committees flag ship seems to be controlled by Soingrass.

Blue Line is the preliminary to Yellow Line, which is the preliminary to Red Line
Not sure if it's been outright stated, but people make reference to Blue Line, such as the TV reporters claiming Miki and Todoroki to be Blue Line champs. I assume blue line is the stage before yellow like. As we know, there were 8 yellow lines, with the winner of each all participating in Red Line, so i think it's safe to assume the Yellow Lines are composed of winners of the various Blue Lines.