Sooo...the dust thing is kinda cool. I think it needs toned down just a tad though. Pretty easy to stir up a cloud so big and thick you can't see a damn thing. But I'm sure if I did a little comparative analysis I could figure out how to adjust that myself.
Anywho...one more thing. I noticed this a while back when I was attempting to convert my ST mud mods to MR. You can't really do anything to the <Mud><Substance> lines without causing things to get a little, more or less, weird. I never noticed it with ST(but that was a long time ago, and I might not have looked hard enough).
What am I getting at? What I call the "Runaway UAZ Problem". I'm not sure what all vehicles it affects. But for sure the UAZ. Not sure if it's because it so light. Or something to do with the wheels. Or both. Or...I don't really know what. But it appears that the <Mud><Substance> values are tuned PRECISELY to eliminate it. It doesn't take hardly any fiddling around with those values to set it off. Particularly, but not necessarily, things that would make the mud "easier". And your mod sets it off nicely.
What exactly is the problem? A UAZ that gets sucked along through the mud/dirt without any throttle being applied. Kinda hard to explain in so many words. So I made a vid to show it.
What you need to know before watching is that at no point after the 0:16 mark did I touch the throttle at all. Oh...and this is with your mod minus the textures and dust.
Youtube Video
If you're interested in fixing it. I did a little messing around and seemed to be able to make it a little better just by lowering the SubstanceFriction(from the value you set it at). It didn't seem to alter your mod in a way that made it much(if any) less effective either. But I didn't really test it out very much. So YMMV. Just shooting some ideas at you.