As for the mechanical components of the car - the modern Bug is a diesel (non-PD) so has a common rail fuel system. I can read fault codes with the OBD2 mechanism but not everything is accessible.
Both tremendous fun but the modern one is 100 times more complex and I would struggle to maintain it single-handedly. But I don't feel the need to reduce the modern car or "fix" the issue of its complexity simply because it is more complex.
My wife has a Mini that has developed a fault but who knows what sensor has failed according to the OBD2 codes?! I don't feel the need to "fix" that and reduce it to the old 1991 Mini Cooper I had (which had its own set of baffling problems, like in-line fuses for important things like the injector but a fuse box for non-essential things like the interior light..... but that's another story).
Cars are not a good example to point to. The thing that would make cars a good example would be if cars were shown to exhibit a steady increase in essential complexity. In that case, yes, we might point to them and say, "Maybe the situation for software is the same, and we're mistaken to have any unreasonable expectations to the contrary?" But that doesn't match reality. Car manufacturers are as guilty as software developers of producing things that have gotten steadily complex without good engineering reasons to justify the complexification.
(Pre-emptive request: please do not respond to this comment as if I'm arguing that cars have not become safer or more fuel efficient.)