Morning sun found a new Mustang
Abandoned in a Wal-Mart parking lot
Blood on the seats, so don't tell me away

The story:

I thought it was kind of odd that she said that in the song. It's such a fun upbeat song, and that line always made it seem to me like she murdered the guy, abandoned the car and asked witnesses to keep their mouths shut. Then I saw the music video and it all clicked.