Teabag: Many thanks!

the lighting is a hdr only, no emitterplanes were harmed in the creation of this image heh..
Peter: Yes C4D permits maps to be baked, but for that to work well the object needs to have UV's (unwrapped mesh) and this mesh is quite dense, around 450,000 polys if i remember correctly and my machine simply choke on the mesh and crashed when i tried to unwrap it. That's part of the reason why i went for this postwork method of merging in the dirtmap, otherwise i woulda baked it.
Here's a older testrender i did using a Evermotion figure to test how well baking of dirtmaps works within C4D and if the object has UV's of some sort then it works quite well.
Dirtmap rendered with C4D (unbaked)
Dirtmap rendered with Maxwell (baked) note: scratches are added by me in Maxwell's material.
/ Max