In the UK a WV is more than likely to be a diesel and may have less strict pollution controls so the engine may start and run with no computer controls so without knowing all the deatils of that test its not a good example. Gas engine vehicles in the US have a lot more complexity than other parts of the world. For example my truck has an engine computer under the hood which communicates with the body computer and computer in the instrument cluster via a network like data bus. Then there is a small computer in the ABS and SBA systems as well as one in each door and another for the air bag which all communicate on the data bus. And mine isn't enev a high end model which have more bus connected compueters under the seats and in the entertainment systems and tracton control, etc. OTPH modern electronics are in some ways more robust. In the 60's when the military conducted EMP experiments electronics were simple. A single transistor was simply a transistor, now that package looking like a transistor has a transistor with over voltage, over current, over temperature, etc protection and the circuits they are built from have several protection devices also. Then the vehicle systems are made a little better protected as well. My truck has a small fuse for nearly every electrical item and then those are fed from branch circuits with larger slower acting fuses and then finally a main fusible link. So there are three levels of fuse protection for any device and I of course being prepared have enough spares to replace them all if needed.