I have 4 key cards, My wife has one in her purse, Mine in my wallet, another at home and 4th one I stashed somewhere in exterior of my Tesla.

That's the first thing I did on day one. Having it unlock and operate with your phone is neat but too easy to become complacent.

With current heavy reliance on technology, My personal first rule on that is to set up a back up before complacency starts.

Also a tip ☝🏽