Join Date: Jul 2004
Location: Live: IWI; Work: DCA/Everywhere; Play: LAS/SJU/MLE
Programs: AA EXP, DL PM, Hyatt Glob, Marriott Ambassador/LTP, Nat'l Exec Elite, LEYE Gold
Posts: 7,422
If you say something, you're almost certain to be charged.
If you don't, you're almost certain not to be charged. If you then did nothing, that would seem improper. But if you deposit the keys with a note into the mail (or indeed in to any National rental drop box), surely you'll be just fine.