Guts. That’s what it took for Tim Ellis, global ad director of Volvo, to sell his Mystery of Dalarö campaign internally. Ellis admitted as much during a presentation on viral advertising last month in Cannes.

A cult success, the two-year-old multimedia effort by Euro RSCG started with a mockumentary recounting how 32 families bought the Volvo S40, on the same day in a small Swedish village. It encouraged viewers to check out a Web site for more info. Ellis says the objective was to snare a younger audience and move away from its ‘old man in a hat’ target imagery.

Problem is, the suits in the boardroom at the Swedish-based automaker balked. ‘You have to fight like hell and you can’t agree to compromise,’ says Ellis in explaining how he got buy-in. Originally, two-thirds of the company was against Dalarö and he worked to reverse those numbers.

Fortunately for him, the viral effort was a smash, catapulting Volvo to number one in awareness (while only number four in spend), and shattering all previous sales records.

Since then, the auto brand has continued down the same path. Its recent campaign, ‘Life on Board,’ is equally quirky, featuring a Web documentary of intimate discussions between Volvo drivers and passengers, such as successful stockbroker Chris Gardner (who was once homeless) and psychologist Richard Wiseman.

Strategy cornered Ellis after his speech to find out more.

Where did the idea for Dalarö come from?

The main idea came from the agency. It then developed with the director Spike Jonze. His idea was to make it truly authentic so that people would actually debate whether it was real.

How do you keep the momentum?

The ‘Life on Board’ is a major step forward. Everyone can identify with the powerful, intimate conversations that go on in the car. People automatically feel, ‘yeah, that’s what it’s all about – being free, safe and comfortable in the car,’ and of course, as they’re watching this branded entertainment, they begin to take in the messages we want them to take in. So it’s a very unusual, implicit way of selling. That kind of honest and authentic way of communicating, that’s the way forward.

Just how difficult is it to take risk in the auto category?

There’s so much money put into the launch of a car, that if it doesn’t go right, you’re dead. So you have to, to some degree, guarantee success. Let’s face it, if things screw up, you’ll never be blamed for doing something conventional. But if you do something unconventional and things screw up, you’re in big trouble.