If I had a barnyard affixed to my car by the Angel of Arc, I'd consider finding a way to incorporate it into the car for posterity... you earned it, it's a fun piece of history.
BUT, I'd do something like maybe weld it flat and paint it into your theme or something like that. A "fresh" barnyard welded to your car indicates that someone on your team is driving like ass. Not necessarily a message you want to send to the other drivers (or the theoretically impartial corner workers, or the totally impartial judges) during this race.
If you incorporate it into your theme, you wear the badge, but it's clear that it wasn't THIS race you were driving like ass at.
Lemons South 2008 - Fail, Lemons South Spring 2009 - Fail, Lemons Detroit(ish) 2008 - Fail, Lemons South Fall 2009 - Fail, Lamest Day 2009 - Fail, Miami 2010 (Chump) - 2nd!, Sebring 2010 (Chump) - Fail, Cuba 2010 - Crew Chief, Roebling 2011 (Chump) - 8th!, Sebring 2011(Chump) - 19th!