just to inform about progress i've done so far:
1) i took the original race engine, as there's no point in rewriting ~8k lines of code if the original one is tested and proved stable for over 3years long.
2) made foot races, together with foot spawns, foot pickups, and handling finishing/ranking as passenger correctly( passenger cannot win). Of course there are some bugs yet, but not enough testing yet is made to fix them all.
3) grid system is mostly done, together with ranking.
Idea under the grid system:
If ghostmode is enabled : players in your grid is half-transparent, uncollidable, in other grids-invisible.
If ghostmode is disabled : players in your grid is fully opaque, solid, collidable, in other grids - half-transparent and uncollidable.
4) few interface tweaks, the numeric car plates, and few other little tweaks i've done just while passing by the code.
As ill manage to test and fix foot races and grids to the point none warnings/errors will be caused in a while ill try making SK/IV gamemodes, some kind of score/win streak/duel system, and most importantly - ability to exclude players from race script for, say, /tv or /freeroam.
If someone is wondering about hi-scores, traffic sensors, map management and loading, hi-score "ghosts", split times, that is done already by addons available on community.