I have a similar set of keys on my RV key ring. One morning I left it on the bumper after hitching up and drove away, using my Truck keyring. Retracing my steps I found what was left of them in the road, run over by a hundred cars. Surprisingly the only ones beyond repair were the ring itself (pretzel), the key fob to my bicycle alarm (completely disintegrated), the round hitch pin key, and the trailer door key. Fortunately I had spares for the hitch and door.