Just because most of us drive cars doesn't mean we have be able to build them or design them. Often times an engineer is just someone who makes science accessible to those that aren't technologically inclined. If we've done our jobs well, we've eliminated the need for knowledge of absolutely everything that isn't critical.
Indeed. For the Baby Boomer generation, it was a critical survival skill to be able to perform all general auto maintenance procedures yourself... everything from changing fluids to rebuilding a carburetor. Everyone either had to learn to do these things themselves, or collaborate with friends and family to get them done. Cars broke down all the time, and having a mechanic do it for you all the time was not generally an option.
These days, advances in auto engineering have made some of these processes less necessary, and others of them less accessible to those without specialized tools and training. As a result, these are no longer necessary everyday skills.
For Generation X, the critical skills are around electronics, specifically the abilities to manage your own PCs (hardware and software), set up and manage home networks, etc. These things are ubiquitous and require regular attention at least as often as '60's muscle-cars did, so again you either need to be able to do these things yourself, or get friends/family to help out on a regular basis.
Nobody knows yet what the critical skills will be for our little ones, but I'd say a lot of the current skill set is already headed for obsolescence, because as miniaturization continues in the computer industry, the idea of building and upgrading your own desktop system is going to fade away.
