With gross margin on the sale and new vehicles still hovering below 5 percent last year, dealers continued to look to the F&I office to make up for lost profits, according to the National Automobile Dealers Association's 2011 NADA Data report.

Aftermarket income rose in 2010, with a 15 percent lift in F&I dollars and a 7 percent increase in service contract dollars from 2009. Penetration rates on service contracts also picked up last year after rates dropped to a four-year low.

"The ability to obtain finance for customers improved, too," the report stated. "A renewed focus on F&I, resulting in higher finance penetration rates for both new and used units, and a greater emphasis on customer understanding and satisfaction in F&I yielded better performance."