Good point. It isn't like the wheel would have to be reinvented, and there will be numerous examples out there to figure out things.
More primitive vehicles will be at a premium for a while...and anyone with a pre-computer auto/truck could stash spare critical components where they'd be safe from an EMP or Carrington event. (Starter, coil, points, generator/alternator, condensors, light bulbs, etc.)
I was watching Mountain Men a few weeks ago. One guy made fuel for his truck from firewood {chips}. He said it was a method used back around 1900 or so.