I musta heard this album a thousand times, as it's what my caving buddies always played on the way to going caving. My brother bought me the tape way back when after I told him about that. Here's the verse in question from Copperhead Road:

Now Daddy ran the whiskey in a big black Dodge
Bought it at an auction at the Mason's Lodge
Johnson County Sheriff painted on the side
Just shot a coat of primer then he looked inside
Well him and my uncle tore that engine down
I still remember that rumblin' sound
Well the sheriff came around in the middle of the night
Heard mama cryin', knew something wasn't right
He was headed down to Knoxville with the weekly load
You could smell the whiskey burnin' down Copperhead Road

It makes more sense when you see the whole thing. He used the primer to get rid of the Johnson County Sheriff mark!

www.steveearle.net/lyrics.htm