Gaius Appuleius Diocles' Chariot

Origin
Gaius Appuleius Diocles was a 2nd Century charioteer who was known for having one of the longest and most prosperous chariot racing careers in history. By the time he retired at 42 (unusually old for a choriot racer) he had won over one thousand races and ammassed a totla fortune of over 35,863,120 sestertius in winnings, enough at the time to supply the whole city of rome with food. He is regarded as one of the best paid athletes of all time

Effects
It is unknown if the charioit had this effect before Gaius became such a success, but it would go a long way in explaining his constant victory. No matter what is thrown in the way of the chariot, no matter how unruly the horses and no matter the roughness of the terrain, the chariot will never crash. Circumstances will either play out in almost impossible ways to avoid collision orIt will simply bounce off obsticles as if they were rubber.