hah, its even easier.
just go into ur directory, rename "base.scs" to "base.rar" open it, change everything u want to, save it and play.
havent tried changing stuff yet, but im going so im not sure if it will work.
one important thing i just found out, do NOT open the files inside with notepad, otherwise they will be corrupted, u will need something like Visual Studio or similar.
another edit, well that didnt work too.
edited one file, saved it and tried - crash.
even with original values.
strange.
have to test further to find out whats causing that.
Okay i've been playing about and i've got the speed to work, along with transmission and brakes.
I decided to floor it after putting torque to 1999. I then smashed into a rock and it went dead horizontal. Then froze and claimed I'd completed the mission with -50000 in driving offences.
When you've changed a file within "base.scs", make sure you store it and not compress it.
I tried to make a in-car cam, it's useless (and looks shitty, no inside textures). It still behaves like an external cam, so if you make a turn, the camera turns a little bit slower.