Would it be possible and practical to model cars and other vehicles in moi in a similar way to this :
http://youtu.be/yX4SRsyKYpE

In short, yes.

Long answer - depends on the type of surfacing you need on the output end. If you are making toys, models for games or just because, MoI is great. If you are making a real car and need certain types of surface continuity then maybe not.

Attached is from when I was messing around with a tutorial for car building in Rhino that works in MoI as well, commands you use sometimes are different and will have different names so you do need to have some ideas about how surfacing works so you can pick the right one to use. Even then, with the simple UNDO command and how quickly MoI bangs out surfaces its a non-issue to be wrong a few times in a row.

Explore this! (making of)
By Cristobal Vila

http://www.etereaestudios.com/docs_html/nixus_htm/nixus_index.htm

Just keep in mind that vehicles are one of the most difficult kinds of models to create, they basically require a more advanced toolset and higher level of understanding of surfacing tools. So there is a much longer learning curve involved with doing those types of models.

- Michael