Currently the game are under development, uses Box2D for physics and 'TMX Parser Lib' for read 'tmx' maps (yep.. I use tiled map editor).
The map can be virtually 'infinite' (clipping and using quadtree), in this video I only spawn 7 A.I Players.. can see that the 'clipping' method doesn't looks bad...
For 'cars' A.I Players.. i'm currently using an a bad "A+ Pathfinding" implementation :S (need be reworked)... with Manhattan heuristic.
The lighting system it's very simple but works pretty good
only use a sprite for create the spot light and a 'RenderTexture' for generate the lightmap.
For tile map rendering i'm using textures with size power of two and vertex array.
The Particle system is the same that i made for 'FingerShip' game... but with possibility for define light particles.
http://www.youtube.com/watch?v=12FQuLDxAP8Cheers!
** Sry for my bad english :\