It may not be sexy, but it's a fact: The u.s. car market is driven by used cars. The challenge for automakers is matching their inventories of spiffed-up off-lease cars to buyers. Honda solved it with a custom searchmarketing program that got buyers to certified pre-owned vehicles in their towns. The company moved its tv ad budget into network radio and a new search-engine marketing campaign on Google and Yahoo. The effort included custom Web sites listing hcuc inventory - model and year - in Honda's 40 lead markets for certified usedvehicles depending on the location of searcher. The sites used geo-targeting, mapping and databases to customize listings with photos, maps, listings, and access to warranties and other info. In the first eight months last year, hcuc sales were up 13.9 percent versus the year before. The campaign netted a 780 percent increase in leads.