Motion Blur while using CINEMA4D as the Composition Renderer

I have achieved a similar motion blur effect by adding an adjustment layer and applying Pixel Motion Blur Effect directly to my Comp with Cinema 4D Rendering enabled.

Sorry, I was tired. I completely missed that you were using the C4D rendering engine.

To enable motion blur when you are using the extrusion or bending tools available in a comp with the C4D renderer all you have to do is nest that comp in a new comp with the Classic Rendering engine enabled and then collapse transformations. That's all there is to it. Here's all of the modified properties of both comps revealed and the composition settings for Comp 2 showing a jacked up shutter angle to exaggerate the effect: If the angle is right you're done, if not you need to use another copy of the extruded comp without collapse transformations turned on. This will work well if the extrusion is not too extreme.

If that does not give you what you want then you can simply add the CC Force Motion Blur effect to the nested layer and adjust the shutter angle to match your other movement. The only problem with CC Force Motion Blur is the render time. It can get pretty crazy when combined with extruded layers.

When you are using the C4D renderer and you need things like blend modes you can access almost everything on the disabled list by simply nesting the comp in a comp with a the Classic 3D Renderer enabled. You just have to play with the collapse transformations modes to make some of them work and sometimes you have to nest then nest (pre-compose) again to get the rendering order to do what you want it to do.

Enable motion blur on the layers, adjust the options in the Composition Settings Advanced Tab, and make sure you have Motion Blur preview turned on in the Composition Panel. If you don't know what I'm talking about then type Motion Blur in the Search Help field at the top right corner of AE and study the help files. Everything you need to know about how to do it is in there in detail.