Sorry to be pessimistic but what's to stop someone using a RFID reader to read and clone your card or key fob. RFID is used in building security but due to the easy duplication and vulnerabilities high value or dangerous rooms are still key controlled as they can't be cloned blind (unless the key number is in open sight).
RFID can even be cloned just from walking past you with the correct equipment which is why new contactless cards are vulnerable and thus limited to £30 transactions.
I did mention that , the rfid is only for opening the car still need and ignition key or Hotwire and break the steering lock, I have a quick release wheel so they would also need a quickrealse wheel with the matching couple. The range of passive RFID is also tiny less than and inch.