retopologizing large irregular ngons This Toyota logo is a topological mess. Initially it was just a large circle plane, extruded, with no cutouts. Then, it got messed up after using a boolean difference modifier. It actually looks better than before because I ended up deleting a lot of extra faces and filling in new ones. The main problem with this is the faces of the object which are large asymmetrical ngons.
I now assume a much better way to have done this would be with curves and knife project but am retpologizing this as a learning exercise.

I am pretty new to blender. I used to use it several years ago but have memory issues and am now relearning everything. This is my third model.

I know the first step would probably be to connect the vertices of the cutout edges and dissolve non-matching vertices and edges. But I cant always do that for edges What I am trying to do with this model is chamfer the edges of the cutout areas. Is this possible even with tedious work or is it a lost cause? Also, would it have been better to keep the main two faces of the disc as a circular ngon or should I have used fill grid before applying the difference modifier?

The file is at http://www.pasteall.org/blend/33200
For popular and common items it might be a good idea to search for wireframes other people have made in order to learn from them. For example sites that offer 3D models for sale.

Here's one I found. 
I post it here for educational purposes: