some believe it was nissan or their advertising agent, omd, behind it. Nissan has no say, they never confirmed or refused this, even though they tried to make it seem like an outside job.
It was a form of guerilla marketing. I do agree with the secrative nature being an ingenious ploy. It created a buzz about the vehicle that touched upon its emotional ties to pop culture and heritage. Many other car manufacturers have done this in the past with success and failure.