Are there any allegorical elements in the story "The Life You Save May Be Your Own"?

In Flannery O'Connor's "The Life You Save May Be Your Own," the key to one allegorical elements lies in the name of the male character, Mr. Shiflet, who could easily be the prototype for the worthless, lazy type.  He also represents the conniving, selfish type as he expresses interest immediately in the old woman's automobile that has not worked in years.  This glance at the car calls the reader's attention to the title taken from the old billboards of the South that read, "Drive carefully, the life you save may be your own," a billboard that encouraged self-interest.

Indeed, the life that Mr. Shiflet saves is his own.  Of course, Mrs. Crater has her own interests in mind as well.  When, for instance, Shiflet suggests that he is a carpenter, she realizes that he can be useful to her.  Also, there is a suggestion of a savior since, Jesus, too, was a carpenter.

In an allegory there is more than one level of meaning--a literal one and one or more symbolic meanings.  In Part II of the story, "The Resurrection," Shiftlet gets the old car to run and 

with a volley of blasts, it emerged from shed, moving in a fierce and stately manner.

At this point, Mrs. Crater offers her daughter, Lucynell, to him.  Shiftlet, in his self-serving manner, replies that it takes money, displaying the avarice of the devil: his smile "turns into a weary snake."  Mrs. Crater succumbs to the "snake" and offers Shiftlet money and nature's darker side emerges.  Thus, the exchange between Shiftlet and Mrs. Crater's is more than a temporal one; it is a spiritual descent into falling for the temptations offered them.  The "savior" has transformed, revealing his devilish, shiftless nature.  Certainly, he is no Jesus.  The missing limb of Shiftlet marks a character who is not new; one who has already sinned.

Shiftlet's betrayal of Lucynell comes in the third part of the story in which he claims she is no more than a hitchhiker and abandons her.  Afterwards, Shiftlet was "more depressed than ever," so he picks up a boy who did not even have his thumb out.  As Shiftlet tries to recreate himself--as the devil does--by telling the boy romanticized stories of his mother, the boy interrupts him, flings the door open, and jumps into a ditch.

This action "shocks" Mr. Shiftlet.  He feels that

the rottenness of the world was about to engulf him....'Oh,Lord!....Break forth and wash the slime from this earth!

After a short time, there is a peal of rain and cracking thunder.  Although he steps on the gas, the storm, the "galloping shower" follows him into Mobile as he seeks to elude his washing from the earth.