Even high school business courses teach that you should produce only what the customer wants. But this is a lesson the automakers have had a difficult time learning.

In his autobiography, Lee Iacocca mentions that when he joined Chrysler to help turn it around, the company was building cars that neither customers nor dealers had ordered.

This led to Chrysler manufacturing cars with lime green paint, a four-speed stick transmission and various other options no one wanted.

But these cars were forced on the dealers and sat on the lot while floor plan interest ticked away. Eventually, they were sold--usually at a loss to Chrysler and the dealer.

During Iacocca’s tenure at Chrysler, a majority of new cars were purchased from a dealer’s lot. This is still true today. The rest are ordered the way the customer wants them.

Therefore, it’s the dealer who really buys the cars and hopes they’re what customers desire. It’s also why dealers need to move cars. Otherwise, they are paying heavy interest for keeping them on the lot.

Last month, at the 2010 Automotive News World Congress, Mike Jackson, the chairman and CEO of AutoNation, a conglomerate of auto dealerships and brands, said the dealers were growing weary of the U.S. automakers forcing large inventories on them. If the dealers didn’t add cars (often, they had nowhere to put them, he says), they wouldn’t get hot-selling models or other cost-reduction incentives from the OEMs. This created a contentious manufacturer-dealer relationship.

While I was at the congress, I found out that for many years, Ford had been building cars without having customers for them. The company had been just keeping its assembly lines moving.

This all changed, however, when Alan Mulally, president and CEO, joined Ford in the fall of 2006.

Mulally recognized that pushing vehicles into the marketplace with no customers also caused vehicle pricing problems. The automakers had to give big discounts for fleets, and residual sales values dropped, meaning customers had to pay more for leases. All this made Ford lose billions of dollars.

Mulally ushered in many changes at the company, and under his leadership, Ford was the only member of the Big Three that didn’t take a government bailout or apply for bankruptcy protection. In January, a USA Today columnist described Mulally as "Detroit’s new rock star."

As part of its new sales/manufacturing precedent, Ford had to go through some wrenching changes, such as mortgaging all its assets and downsizing (or rightsizing) to balance its manufacturing in light of diminishing sales all the automakers were experiencing.

I hope the "new" Ford will make it. I think it will, given Mulally’s enthusiasm and leadership.

I also hope automakers learn from history and don’t build cars without customers. If they do, history will likely repeat itself. And that wouldn’t be good for anyone.