How does it work?

When the player moves in a vehicle, the mod will find all objects in front of the player that could be collided with.
Then, it figures out which of those objects forms the closest 'layer'. E.g, the closest row of trees in a forest.
Lastly, it places a warning icon above the closest layer of objects via a custom particle.

Can I turn it off?

Yes! Hit 'i' while driving to toggle it.

Does this work with custom vehicles?

I haven't tested this, but it should! It simply checks if the player is driving a vehicle. It doesn't care what vehicle you're in, aside from a few exclusions.

Will it work in multiplayer?

Try it and let me know if you have issues! Nothing should prevent it, as it's all based around a player. Adding more players shouldn't be a problem.