Introduction
When modeling a car I generally try to find something different to build, something I haven't seen before (in 3D). I enjoy modeling older cars because I find their shape more fascinating than modern cars. Sometimes I have an idea of the final image I want to achieve. Originally, I was going to try and get the Peugeot to look like the reference pictures I had sourced, but then I stumbled across a few rally cars and decided it would be fun to texture the Peugeot with decals, mud, rust, and so on.
I had the Peugeot almost complete in its standard form before deciding on the final image I wanted to create, which then involved further modeling and texturing. These additions definitely made the final result more visually appealing.
Modeling
The first step with this piece was to get some reference pictures and a blueprint. Finding as many pictures of different angles and close ups of certain details as I could was definitely helpful.
Then in Softimage I created some profile curves. I used the curves as guidelines (not to actually generate any geometry from) and I used polygons to model (cube, sphere) (Fig.01). I modeled one half of the car first and then when I was happy with the shape I used the symmetry function to create the other side.

Fig. 01
The way I generally start modeling a car is by doing one complete wheel first (usually the front left one for some reason) and then building up the car's basic shape from there (Fig01a).

Fig. 01a
Once I had the basic shape of this particular car's body done, I went in and added the finer details (creases and bevels).
To start with some areas didn't look resolved, but as I added detail and kept switching from subs (sub-divided/smoothed version) to hulls (low poly) it came together. That was the hard part (Fig.02).

Fig. 02
All the extra bits that made up the finished car were modeled after that (Fig.03 - Fig.05). The modeling was quite straight forward; it was just a matter of getting the curves and creases in the correct places.

Fig. 03

Fig. 04

Fig. 05