Traffic and Weapon Randomizer. (Buggy / Possibly abandoned)
Why? Love this because I just like randomness and this script fulfills my need. Source code is available.
However, it's very buggy and the author hasn't responded for 10 months now. The biggest problem is that this script keeps spawning vehicles infinitely without replacing any parked vehicles and roadblocks, which after a little bit destroys the framerate and even crashes the game.
The vehicle speed option in the .ini doesn't seem to work at all.
When police helicopters get replaced while in a chase, they will always flee. And the AI doesn't really seem to know what to do with planes sometimes.
At last, it would be really cool if mission vehicles can get changed. Doubt it's possible though sadly without instant mission fails/crashes.