LOKIOLR

I can confirm the 6th parameter in the STREAM section is for degree of variation. Not sure if the value stands for actual degrees or a percentage but the larger the number, the larger the random variation is. A value of 0 will not vary from the angle defined in parameter 4 and 5.

LOKIORL
You are make out some parameters in 'cars' section? I mean flags.
If yes - please, write it in your post..

I'm not 100% positive on the 12th Parameter in the cars section. It's either car groups or some sort of flag. Based on some trial and error experiments that was what I came up with. But the UNKNOWN 3 in Section 0 is draw distance for sure. I use it to create some mock LOD objects for my map edits.

I will look into it a bit more once I finish working on the car rotation stuff.

Car rotation's a vector[X, Y].

From GIMS IV:

dline - WPL car section instance parameters array

Read:

Angle = (acos (dot (normalize [dline[4],dline[5],0]) [0,1,0]))
if dline[4] > 0 then
	Angle *= -1
TheCar.rotation = Angle

Write:

Angle = (TheCar.rotation as EulerAngles)
dline[4] = (sin Angle.z)
dline[5] = (cos Angle.z)

6th parameter deals with car spawning somehow(I've figured that there's only 2-3 values when car spawns, one of them - 4.0757)

Thank you for your help. I thought the 12th parameter controlled when the vehicle spawns. Well more like, the 12th parameter defines the car group (which vehicles to spawn when a hash isn't defined in the 7th parameter), and that defines when it spawns. When I first started to figure out the vehicle spawning I had an issue where my spawns would only appear at night. Now I use 1633 for everything and they appear at all times of the day. Also I've put a bunch of different variables in the 6th parameter and it hasn't seemed to make a difference to whether something spawns or not. If I figure out what it does I'll be sure to follow up here. Thanks again.