Scatter Material (maps ie; jpg, bmp,png, etc.) similar logic to the new scatter where u can distribute grass/vegetation using presets or mappings…
reason being this is gonna be helpful in making realistic walls/roads/ or any item that needs a patchy look using different materials…embedded on top of each other.
basically its like ur painting…
thanks… 
KUDOS to d5 for doing the best improvements and fast updates with regards to the betterment of its product.
- NB still D5 does not posses additional variety of CARS/VEHICLES hoping it will be updated more…rather than getting stuck with these few current cars…