Well, I started in the world of 3d modelling around 1994, when I got my first PC, working with freeware programs of that time and its limitations.
Later I bought an educational copy of 3dStudio R4 for MS-DOS and learned just by testing alone at home, at a time when there was no Internet, of course, and the only way to learn was to try by your own.
Over the years I've used all kinds of software, but currently I'm working with blender, though used for many years to 3d studio, it's still hard for me to adapt.
The project of the post-apocalyptic car was born as a result of a contest organized by a youtube channel,
scratch attack, due to create a vehicle through any DIY technic, set in a post-apocalyptic future, in relation to a Spanish 28mm miniatures wargame, called "punkapocalyptic".
My idea was to get away a little of the typical muscle cars of the Mad Max movies (the original, the actual movies... not the 2015 film XD), the Ford V8 interceptors, and work with some vehicles more related to Spanish tradition.
I made several car bodies of the 80's besides the Seat Panda (Renault 5, Ford Fiesta, Seat 127) but in the end I decided on the Seat Panda because it was the car one of my uncles had when I was a child ... and I think it would be very capable to survive one or even more nuclear holocausts XD.
Once the body was modelled, with the idea in my mind of using truck wheels and add some homemade looking caterpillars that could been placed or removed depending on the terrain, I started taking and joining parts of my own 3d models library until I got the final appearance, like a "Frankenstein" puzzle.
In the end, I could not participate in the contest because I spent lots of time optimizing the model for printing and I was out of date, but it was a very fun project and I've enjoyed a lot modelling it.