Not quite the same. Is there one manual that works for all cars?
Experienced mechanics only need manual for certain things like how much to torque the head bolts on a specific engine - note it may not be same for all engines, or occasional things they do not run into very often. Now today's cars are complicated enough there is probably more use of resources to help work on them then there used to be. The electronic diagnostic equipment of today also makes troubleshooting somewhat easy for many common problems though. Just plug it in and it tells you what the problem is or narrows it down to a small list anyway.
When will we have the day when a homeowner has electrical problems, calls a repair company, they come out and plug in a diagnostic machine into a port near the main panel or meter socket and it will tell them what is wrong and where to go to find the defective equipment?
Same goes for my use of NEC. Outside of using ampacity tables, raceway fill tables, motor current tables, and a few other items like that (and even some of the most common used parts of those tables I have memorized) I don't have to open the NEC for everything I do. But I do know how to find what I need when I run into something I don't know or am not quite sure about.