Eighty percent of vehicle shoppers just show up at dealerships, according to a recent study by Northwood University and AutoTrader.com

Dealers tended to think “a lot more” customers arrived with appointments than actually did, says Howard Polirer, AutoTrader’s director-industry relations.

Of the few surveyed consumers that had scheduled appointments, 17% did so by phone and 2% by email.

The walk-in customers offered different reasons for what prompted their visits. Thirty-one percent said they were driving by, 27% cited advertising, 22% mentioned prior experience with the store and 20% referred to recommendations from family or friends.

Of those shoppers brought in by advertising, most (54%) cite Internet ads as primary motivators. Classified magazine ads (15%) and newspaper advertising (13%) were next most effective. “There is still a place for print advertising,” Polirer says, while touting the growing influence of Internet marketing.

He describes virtually all dealership visitors as “Internet customers,” because the vast majority do online automotive research or preliminary shopping before heading to the dealership.

None of those surveyed said outdoor advertising swayed them. Those highway billboards with giant images of dealers “may impress dealership people, but they’re not very effective at getting customers into the dealership,” Polirer says.

Northwood students and Morpace Inc., a market research firm, interviewed shoppers in 17 markets nationwide and at a variety of dealerships representing different brands, both luxury and non-luxury.