Keep in mind that the relays of the same size in the power distribution center are all interchangeable with each other. So if an important relay stops working, you can always pull the horn relay and replace the bad relay with it.
One thing to never keep in the glove box? Your registration and proof of insurance. Keep a copy of those in your wallet. That way if your Jeep is ever stolen the thief won't have them to give to the police if he gets stopped. That's a good clue to the cop something's not right & he'll figure out it was stolen.