SANTA MONICA, Calif. –

The surge in new-vehicle sales dealers enjoyed during Labor Day weekend apparently isn't sustaining as September rolls along.

Edmunds.com analysts believe the current pace of sales could leave the SAAR for this month at 11.3 million. They said that rate is assuming slightly lower fleet sale volume than August.

"New-car sales for the three-day weekend jumped a remarkable 22 percent compared to average weekend sales in August, rather than the typical 12-percent rise," noted Edmunds.com senior analyst Ray Zhou.

"But as soon as the holiday weekend was over, car-shopping activity fell about 40 percent," Zhou added.

So far this month, the site contends BMW, Chrysler, Ford and Volkswagen retail sales all are down between 5 and 10 percent compared to the first two weeks of August. However, analysts believe Nissan is up about 5 percent and Toyota sales are about 9-percent higher.

Edmunds.com thinks the rest of the automakers are relatively stable.

"Labor Day occurred unusually late this year. This took some sales that would normally have occurred in late August in the run up to the Labor Day weekend and pushed them fully into September," explained Edmunds.com chief executive officer Jeremy Anwyl.

Senior analyst Jessica Caldwell speculated about how sales could come in for September and beyond.

"There are no more holiday weekends in September and few throughout the rest of the year, so automakers may want to think about some creative ways to stimulate sales," Caldwell emphasized. "Momentum seems to be lacking whenever the calendar does not reflect a traditional sales period."