https://www.gta5-mods.com/vehicles/semi-realistic-car-physics-v
Sadly I know what you mean by the snow. Similar to how when you go to North Yankton. It was super snowy, with your car plowing through snow and the characters animations are completely different. It's insanity and I don't know why it's not in the regular missions. My only guess is it's due to level design. That snow is actually BUILT into the map and has some sort of unique coding for characters and vehicles.