When electronic ignitions began to become popular in autos in the 1980's auto makers began shielding ignitions system,  not from an EMP, but from auto mechanics or auto owners causing static discharge from connecting, dis-connecting battery cables or from nearby lightning strikes. They did not want to deal with warranty problems from dead ignitions systems. Ever since then, the auto makers have been shielding the solid state electronics in vehicles to protect them. Often the computer is buried on the firewall and very well shielded. An EMP isn't going to effect many vehicles. Many other electronic devices will survive as well.  This article is just more fear mongering.