I had this click in my head whilst I was trying to sleep last night. Taking this directly from my old 'RollcageX' test notes.
I had an idea for one environment where it was, basically, a sort-of sanctioned racing arena/stadium. Roller-coaster-esque sections of track rising and falling, loops, a sort of 'official' vibe to the area that was I guess half-inspired by Trackmania's Stadium arena in its scenery. Big buildings, grandstands (some of them you could drive on), blimps and hot-air balloons suspended in the air. Tons of fake advertisements along the walls of the circuits and cars and the obstacles were clearly fake obstacle-course looking things (big blocks of concrete arranged into poles or buildings or whatever). Think how Formula One or Wipeout would be, except for 300mph tanks that drive on ceilings.
I was just describing it because I was always amused of the idea that, since Rollcage and by proxy Grip are sort of illegal street-racing-type things, there would be a legal racing arena to counter it. There were two 'alternatives' to these stadium arenas that I'd envisioned;
1) The default, as described above.
2) 'abandoned' versions, used after the official events where the crowds have gone, it's night or early-morning, and they've sneaked into the tracks to race when they're not meant to. Maybe some of those Deus Ex Machina barriers that keep the crowds safe from the cars have been turned-off, maybe someone blew some holes in some walls for extra shortcuts... basically just an alternate version only instead of being used legally the tracks are commandeered ..... illegally.
Silly ideas anyway, but ideas are ideas right?