Under "cause of death," the autopsy report won't cite today's many inelegant designs nor will it point to dwindling interest among the populace in restoring and preserving machines that evoke the past. Instead, the cause of death will read: "Obsolescence by extreme infiltration of 1s and 0s." In other words, digital technologies will make tomorrow's old cars unsustainable.

So how will these small parts manufacturers offer, say, a replacement IMA controller for a 2005 Honda Insight when that car is 35 years old? How about a voice-recognition module for a 2006 Lexus GS 430 30 years down the road? Will these vendors have the skills to reverse engineer complex digital parts, and if they do, how will they amortize the cost of a chip foundry cranking out replacements in quantities of probably just a few thousand? And even if they figure all of that out, where will the money come from to defend themselves in court from a phalanx of auto-industry lawyers pursuing an action under the Digital Millennium Copyright Act for intellectual property theft?

Carmakers hold the keys to a car's longevity like never before. Sure, they want their cars on the road long enough to build a reputation of durability, but they don't want it to be so long that you don't come back to buy another one. When your car turns 20 years old (max), the guys at your dealership's parts counter start looking at you funny. They chuckle a little as they futilely look up the part you want for your 1985 something or other. I should know; I have cars dating back to '88, '67, and '66. But if I had been born 30 years later, I'd probably have to take up orchids as a pastime instead.

As a particular model ages, carmakers start to phase out certain parts from their catalog, and trim elements, such as headliners, A-pillar garnishes, and dashboard bezels, usually go first. Small engine parts disappear next, especially belt-driven accessories and odd little valves and relays. Later, even heavy iron, such as cranks, cams, and heads, go poof. But the good news is that all of the above can be reproduced by a competent aftermarket.

A car's digital elements are a different story. The main engine management computer in your car is extraordinarily complex, and you aren't going anywhere without it. And there are typically a dozen other processors in today's cars, all just as complex. Worse, they're proprietary, so once you figure out how to reverse engineer Ford's EEC-IV module, that's it--you've reverse engineered Ford's EEC-IV module. You want to do an older Volvo computer too? Start from scratch. And don't even think about the technology that controls safety gear, such as air bags and ABS. With enormous liabilities, as well as federal and state regulation, nobody will try and reproduce safety components.

Junkyards have traditionally been a source of salvation for old car restoration, but again, regulation is increasingly making it illegal to chase parts for your car. Emissions control and supplemental restraint parts are fraught with legal oversight, and I can see a day when more components go the same way. Imagine needing a new set of batteries for your 22-year-old Prius, long after Toyota has stopped making them. You find a low-mileage, lightly rolled Prius in a junkyard with a good battery pack but are told by the scary guy at the front desk that they can sell those to only a licensed toxic waste recycler. This is the kind of scenario you can count on your car-stupid legislators to create.

A lot of car cynics say none of this matters like it used to, that today's cars are not destined to be classics anyway. I agree that today's cars lack the soul that made yesterday's models so fascinating, but the fact remains that if you like cars at all, the vehicles of your childhood will beckon you in your 40s. It's human nature. You may have memories of being an 8-year-old, riding in your parents' Lexus RX 400h and listening to Maroon 5 on that funky old FM band people used to tune into. But by 2046, when you seek and find that vintage 400h, you'll probably only be able to display it on blocks.