Cityscape Data Structure
http://azz.gouranga.com/files/cds.zip

Do not miss the rest of these gems:
http://azz.gouranga.com/index.php?page=8

GTA Mission Template Description (can be found elsewhere)
http://www.fileplanet.com/19571/10000/fileinfo/2/0/section/General

GTA2 Format Docs (somewhat related ;-)
http://files.filefront.com/GTA2+Format+Docs/;10536;;/fileinfo.html

The unofficial Grand Theft Auto Reference Handbook
http://gta.mendelsohn.de/Reference/

Corrections and Notes regarding DMA GTA technical doument [cds.doc v12.10]
http://www.fifengr.com/gtacars/topic.html

--- other links ---

A Stream-based Time Synchronization Technique For Networked Computer Games
http://www.mine-control.com/zack/timesync/timesync.html

Fix Your Timestep!
http://www.gaffer.org/game-physics/fix-your-timestep/

Car Physics for Games - by Marco Monster
http://web.archive.org/web/20051218060818/http://home.planet.nl/~monstrous/tutcar.html