Rent-A-Saint (another lyrics question)

Yeah, I know that all lyrics don’t mean something specific - but I thought I’d check. Anyone know what a rent-a-saint is? Here’s the context:

“Me and you got a lot to do,
we go rolling from Friday ‘till Sunday noon.
Stop, start a letter. Rent-a-saint in back.
Gonna hit the interstate in a Cadillac.
And we’re rollin’.”

From Better Than Ezra’s “Rolling.”