Wow, this image is F'n cool!

Is this the domain of Inkscape or GIMP? In particular I'd like to know

* How to make such a sharp looking image appear dull? Not just the frayed edges. Everything in the picture is extremely detailed and incredible yet it doesn't look like a crisp image. It's 'warmer'. And yes how do you do frayed edges like that?

* Can Inkscape create this type of car or is that CAD or something?

* How to get the Neon effects behind the car and in the name?

If there are any Inkscape/GIMP tutorials please link. I can't find any.

I'd say you could do that as a Gimp/Inkscape combo. If you are really good you could draw the car in Inkscape, but its easier to just find a suitable image of a car.
You could make the perspective grid and the shapes from the car's trail in Inkscape.
The triangular grid on the car's nose is probably the hardest to do, if it has to follow the car's shape.

About your question on how to replicate the look of the image. Note that this is a photo of a book cover. So there is already some degradation in the image.
If you want more you can add noise, or overlay with a grunge texture in Gimp. Filters can help too.

I dont know of a specific tutorial. But im sure there are plenty out there. You need to know your stuff in Gimp really well to pull this of.
Have look at gimp-tuts.com for example.

Definitely do-able with Inkscape! Although the car itself could take some time - maybe as much as the whole rest of the image. Or Inkscape + GIMP, as well.

The car's front? 3D.

You can either use the render 3D polyhedron extension on an .obj file for a parallel projection -oh wait, it's in perspective...
Then head over to blender, the newest version can render to svg-s, probably it's just a setting away for rendering it with the 3D faces showing through -though it is inside the toon shading as far as I know, might need a bit of try and error.
example

The reflections? Traced from a photograph.
Or a photograph itself.
Or rendered from 3D, like in blender.

The cracks look raster, you can blend it in gimp with more options.
Having said that, the random parts at the back have a blending mode inkscape cannot provide easily.
(That cube would need a colormatrix filter with custom settings?)