Originally Posted by AutoSlash

There is no "statute of limitations". There have been reports of people being contacted months after the incident with damage claims. That said, a bumper scratch could be written off as normal wear & tear, especially at the major rental companies who are often more forgiving about those sorts of things. Odds are, you won't hear from them so I'd recommend just assuming that's the case and moving on with your life and not worrying about it.