People seem to forget that older cars, along with large generators and trucks, still use electrical systems to start the engine, and keep it running. Those systems are likely to be damaged in the mentioned scenarios.
As for the questions about how badly our modern electronic items would be affected; there are a lot of variables. Start with if they are inside a structure or not, and how much deflection does that structure offer? Are the items connected to any external conductors? The difference in various technologies in the items makes some more susceptible to damage. There is no reasonable way to guess.
I was a military EMC tech, and have worked inside military comms sites. We maintained the NEMP hardened cabinets. Even then, the level of concern about the equipment had waned, so that protective equipment was allowed to be removed as it degraded. Hopefully some of that equipment has been replaced/upgraded.
The best prepping advice related to EMP / Coronal Mass Ejections was this: Get a world-class faraday cage and have your $10 multimeters inside of it. If we have a manmade or natural event, everything doesn't break, but lots of stuff can. Having meters to quickly diagnose broken electrical items will result in the fastest recovery time.
I thought that was pretty sound advice that is low-cost and low-effort preparedness.
Another really great idea I heard of but haven't pursued is to get an old ipad and install the whole wikipedia database for offline reading. If your internet is down and something needs fixing, you probably can figure it out with the world's largest encyclopedia.