Chrysler's Eminem commercial was kept a big secret for weeks

DETROIT (WXYZ) - Chrysler went to great lengths to keep their hit Super Bowl commercial a big secret.

Melissa Garlick, Chrysler's head of advertising, supervised the making of Chrysler's Eminem-Detroit ad. She says she held her breath until it ran, because she was so afraid someone would leak their secret.

The automaker didn't want anyone to figure out what they were up to with the ad that features the Chrysler 200, Eminem and the city of Detroit.

It was originally only going to be a one minute commercial with no plans to show who was driving. That was before Eminem agreed to be a part of it and then the ad time increased to two minutes.

Garlick says she was watching the Super Bowl like a kid waiting for Christmas. She had been so afraid that the secret would get out before the commercial aired.

“When we were done with him at The Fox and driving through the streets, we thought for sure someone would be able to figure it out and uncover us… but we were really lucky and we were able to keep it under wraps," Garlick said.

The commercial was the brain child of an agency out of Portland, Oregon. Eminem was not part of the original plan. They approached the superstar about using his song, ‘Lose Yourself.’

Eminem was reportedly impressed by the positive message the ad was sending about Detroit, so he agreed to be a part of the ad.

CEO Sergio Marchionne spoke directly with Eminem to work out the final details. The project came together in the last three weeks.

WATCH THE FULL AD IN THE YOUTUBE PLAYER BELOW