I want to make my car's texture muddy, dynamic

I think, it would be similiar technology to how bullet holes are draw on walls. But I don’t know how to do this. I mean paint texture on texture, but on point where mud’s particle hitted car’s body.

You may use an approach with decals but a simple way to solve this is to have a mud texture that you interpolate with an alpha value depending on how dirty the car is.

I would crate a small mud texture seperate from the clean car, then an animation in unity. Then play the various animations of mud in different places, depending on that is in the if statement… idk full details of your game but perhaps use a collision detection function. Hope it helped!
SOME ROUGH CODE:

OnCollisionEnter(mud_patch : Collision) {
if(mud_patch.collider.name == “mud”) {
play_animation_1; } }

The texture has to be white where you dont want anything else to show up and I think you have to choose a certain import setting or shader? Thats about all I got.