Neither company released the number of complete transactions that resulted from the program, but according to the Los Angeles Times, the last two weeks produced only 13 sales out of 21,000 listings.

"My understanding from the numbers I've been told is that (the program) drove a lot of inquiries and a lot of traffic but didn't sell a lot of cars," said Peter Welch, president of the California New Car Dealers' Association. "I suspect it was because consumers decided it was more convenient to go to the dealership."

GM spokesman John McDonald called the program a success for increasing brand awareness in California and among eBay users.

According to Rob Chesney, vice president of eBay Motors, their Web site - gm.ebay.com - received more than 1.5 million visits by new car buyers and generated more than 15,000 "high-quality leads" to GM California dealers.

Although the pilot has concluded, the company will consider rolling out a similar program some time next year with some improvements.

"We'd rather do it right in the future than do it wrong quickly," McDonald said.

GM will also continue to offer certified pre-owned vehicles through the eBay platform.

Welch said the program probably didn't generate much buzz among consumers because they already use other online tools to research potential car purchases and don't need another third party to negotiate a price.

"EBay wasn't really needed in between those steps for consumers to make a v decision" (on a car),said Jessica Caldwell, an industry analyst with Edmunds.com. "If they're not going to offer an attractive price for eBay customers, what's the point?"

McDonald admitted that the inventories at eBay were exactly the same as the ones available on the dealerships' Web sites. But he said the key advantage was getting the catalog closer to the eBay audience, who might have a more declared intent to shop and could include consumers who would not normally consider buying a GM vehicle.

The program launched in California on Aug. 11 - a few weeks after GM exited bankruptcy - and was intended to last until early September, but was extended to the rest of the month. Through their Web site, users could find a car and negotiate an offer with one of the 225 participating GM dealerships in California.

Online car sales haven't fared too well for eBay, said IBISWorld senior analyst Toon van Beck. Nonetheless, the end of the program was not likely to disrupt the company's car division in any significant way.

"GM is certainly not a winner as a result of the breakup, while eBay doesn't lose too much," van Beck said. "EBay still has (its) online car sales, but they just don't have the support of this additional player."

E-mail Alejandro Mart�nez-Cabrera at amartinez-cabrera@sfchronicle.com.

This article appeared on page C - 1 of the San Francisco Chronicle