Back in the day, the story was that 2004's experienced engine warning lights due to some sort of transport-protectant gunk applied in Japan that wasn't all removed over here, and needed to burn off.
So the day I picked up my car, I put it on the highway at 70 for an hour up almost to Charlotte, bought a Dew, and then drove it home. The gas came with the car so it was no big deal to me. January MPG was like 40, so I was already impressed over my last car. No engine lights then, and no long-term problems as of 23K miles...