Woods, who first signed with Buick in 1999, will remain a spokesman for the car company through 2009.
'The first four-plus years have been fabulous,' Woods said. 'Buick has totally reshaped their look, design and attitude. I'm proud to be affiliated with the company and very excited about the future.
'Their marketing has made available a side of me that people don't normally see. I think that's been beneficial for me and for Buick.'
'Tiger has been an invaluable asset to marketing across the marketing spectrum,' said Buick General Manager CJ Fraleigh. 'From television ads to print ads to Internet films to dealer clinics, Tiger makes people think differently about Buick.'
Woods is teeing it up in his second event of the 2004 season on Thursday. He tied for fourth place at the season-opening Mercedes Championships but is set for his first title defense of the year.
Woods won the Buick Invitational by four shots over Carl Pettersson last year, his second win at this event after taking his first title in 1999. Woods also captured the Buick Open in 2002.