As you can see from the image, the original dirt texture was white, so I changed its color to make it stand out and look liked dried sludge (Fig.14).
After preparing the textures, I generally prefer to begin texturing from the front part of the model. Therefore the first object I textured in this case was the bonnet of the vehicle. I wanted to add bullet marks on the bonnet, as well as dirt so that it appeared as if it had just came from an armed fight. So I obtained a bullet hole texture from 3DTotal Textures V19 - Destroyed & Damaged DVD
("shell_15") and then I took the alpha channel of this texture, extracted the picture and placed it on the texture I was going to use on the bonnet (Fig.15 - 16).
And at the end of this process, I added the texture to my bonnet. You can see the render below (Fig.17).
Later, it was necessary for me to reevaluate the amount of dirt and slush each part of the vehicle got due to location and proximity to the ground, and I've chosen a lower part - the mudguard - as a second example (Fig.18).
As above, the first texture I used for the mudguard was "camouflage01". This time, I used a different dirt texture - "Dirt 06a" from the 3DTotal Textures V08:R2 - Vehicles DVD
As in the texturing of bonnet, I used this texture to obtain the dirt. You can see the texture and the part render in Fig.20 - 21.