General Motors Co. extends its “60-Day Satisfaction Guarantee” until Jan. 4, part of an aggressive marketing scheme the auto maker launched shortly after exiting bankruptcy.

Consumers can choose between the 60-day guarantee and a $500 voucher towards the purchase of new Chevrolet, Cadillac, Buick or GMC vehicle.

“The campaign is getting the word out about how good GM’s new products are,” Jay Spenchian, GM executive director-marketing strategy, says in a statement. “We’ve seen positive coverage and increased awareness of launch products like the Buick LaCrosse and GMC Terrain.”

GM says more than 99% of buyers who take the 60-day guarantee keep their vehicle.

“Most people, they come in and say, ‘It gives me faith in your product, but now that I’m here, give me the $500,” Vice Chairman Bob Lutz, who took over earlier this year as head of GM marketing, recently told journalists.

GM says the next phase of the program will launch in December, featuring “head-to-head” advertisements in magazines, newspapers and on the Internet.

An element of the auto maker’s “May the Best Car Win” effort, the program’s extension comes the same day Lutz fulfills his pledge to race a Cadillac CTS-V against any challenger with a production stock sports sedan at the Monticello Motor Club in Monticello, NY.

Lutz placed seventh among the 12 challengers Thursday, and the CTS-V captured six of the top seven places, with GM engineer and racing-expert John Heinricy posting the winning time. Other challengers included a BMW M3, BMW M5, Jaguar XF and Audi RS4 driven by local enthusiasts, as well as a Mitsubishi Evo piloted by an automotive journalist.

GM sees the event as successful viral marketing, as the Cadillac lived up to its billing as one of the fastest production sedans on the road today, despite Lutz finishing lower in the standings than anticipated. GM posted updates on the race throughout the day on Facebook and Twitter.

“I haven’t done this in 30 years,” Lutz says in a post to Cadillac’s Facebook page after the race yesterday. “Young whipper-snappers showed me a thing or two. Let’s see them do this when they’re 77.”