Imagine if you could go back in time and tell the guy who first put a cigar lighter into a car back in 1926 that, nearly a century later, that device was still ubiquitous and widely used, but for a purpose completely unlike that for which it was designed. Instead, we're using them to power computers, GPS devices, cell phone chargers, and MP3 players. And it's clunky as heck to do it: the socket is a terrible size for that, the connectors are fragile, the voltage is not reliable without a lot of filtering and processing involving expensive components (and even then there's a lot of hum), and the whole thing is unnecessarily bulky.
So why are we still using it? Clearly, from a technology standpoint, we could have made a better standard at any time in the last fifty years, and the resulting device could have been both better (more reliable, more flexible, etc.) and cheaper (both to build the receptacle and the devices that plug into it). But we didn't, because of the burden of having a standard. No car manufacturer can change the receptacle because of the jillions of devices out there using the old format, and no device manufacturer can change the plug because cars won't have the receptacle. It's like a reversed chicken-and-egg problem.
However, I'm seeing a chance for a way for it to finally change. Almost every device you might want to use on the go now has a means to be charged from a USB port. If next year a car came out that had one of the old cigar lighter adapters and one USB port, probably 2/3 of the current uses of the old adapter could be replaced immediately with a cable you already have. That would save the consumer money without adding anything significant to the car manufacturer's costs. After a few years of this being done, the few devices that you can't charge by USB, but where it would be feasible to charge them by USB, would probably start having a way to do it -- perhaps a clunky adapter at first, but integral, eventually. Then they could stop offering the old receptacle, and someone could sell a USB-to-cigarette-lighter adapter for people who still need the old format for their last few items.
The net result would be a small cost savings for the car manufacturers, another cost savings for consumers, and a great improvement in functionality since the USB power standard is more reliable and uses much sturdier and more compact connectors.
This is only possible because of the ubiquity of USB, but even so, we might not see it happen. It's far easier to keep propogating a ridiculously inefficient de facto standard far past when it made any sense, just because someone has to go first in changing things. This is a key problem with futurism; the change, if it ever comes, will be pretty unpredictable, since a steady state of self-reinforcing sameness will change very abruptly for a reason that probably will depend on something invented not to make that thing change anyway. A side effect of one technology will change the side effect of another technology.