DETROIT—The traditional Big Three automakers are sinking a bit more each year, despite promises that they're turning the corner, and great technology here and there but not everywhere. The North American International Auto Show in Detroit could be following close behind. With apologies to the Motor City, America's new auto capital could be Los Angeles, sooner or later, and the most important auto show could be there as well.

LA finally got smart: On the occasion of the 100th anniversary of the Los Angeles International Auto Show, it moved out from under the shadow of the early January show dates used by Detroit's North American International Auto Show (which is also celebrating 100 shows). Previously, they'd been a day or two apart. Now the LA show is in November. Think about it: Los Angeles in November, Detroit in January. That's strike one against Detroit.

In LA last November, the number of important new car introductions shot up (to 35 total). At one time, Detroit got all the good stuff that was introduced in North America, and LA got a few convertibles and out-there design concepts with bike racks on top.

The greater Los Angeles area has more design studios than anywhere else. And there are probably more U.S. headquarters for car companies in California than in Michigan. Companies support local projects, including auto shows. That's strike two.

Strike three could be the direction of the auto industry. Engine and chassis design is always important, but PC/CE-focused—Bluetooth, audio/video, navigation, storage hard drives— technology is becoming more important, and that's not Detroit's strong suit. California has as much claim as anyone. If you believe the most important aspect of new cars is that kind of technology, not that you don't care about the under-the-hood technology or safety, LA might be a better place.

Then there's Detroit's Yogi Berra problem: That place is so crowded, nobody goes there anymore, to paraphrase Montclair, New Jersey's poet laureate. With 6,600 writers, editors, photographers, and analysts accredited in Detroit this year and only one press conference at a time, the show is just too crowded. Too ossified, as well: To make room for, say, a dozen journalists from a Detroit paper, the NAIAS won't accredit the full-time editor of a car-club publication with 50,000 dialed-in readers. The LA show is delightfully vibrant and welcome to newcomers, but not yet crowded.

An admission: I wrote part of this column in my head after the LA show blew me away last year but before I saw Detroit this year, in a fit of annoyance that the NAIAS and CES shows managed to overlap. For a couple thousand people like me who care passionately about both cars and consumer electronics, this is a horrible conflict that should be avoided by promoters. (Similarly, CES and Macworld conflict for many others.) I had to chair a panel at CES on car technology on what was Day Three for both shows. Arrgh! That said, when I got to Detroit this year, the city was rainy but not unbearably cold and wintry, and the number of intros was higher than what LA had to offer.

But still. Now that Los Angeles has its own time slot with no other international auto show close by, it will grow. And repeat of the 1999 NAIAS-week blizzard that stranded thousands of auto execs, analysts, and editors in Detroit would give that show a black eye again. Unless this global warming thing happens faster than even Al Gore predicts and makes Detroit balmy year-round, another crippling auto-show snowstorm will be Detroit's inconvenient truth.

Last week the Detroit Free Press bemoaned the fate of its local auto show, not because LA beckons, but because the Cobo Hall convention center isn't big enough. Expand Cobo, the Free Press urged, or some other city will be the site North America's biggest show. The paper feared Chicago might wrest away the mantle. Fat chance. The challenge lies farther west. And here's the moral of this story: Motown makes another miscalculation about who's the real competition.