You can get blank keys with a transponder chip that match your car.
You then have to have the physical key cut from one your yours and then program the car to recognize the chip in the new key. I have done this and it isn’t too complex. It was like a sequence of turning at least two recognized keys in a certain sequence and then turning the key to be recognized in a sequence. That is why it is important to have at least TWO recognized keys at all time. Even if you lose a main one with a fob, you should be able to program at least more keys that will start the car.
While the guy was cutting the keys, he accidentally grabbed a basic blank without a chip and cut it. I had to explain that this wouldn’t start the car and that I brought the blanks in. He was going to throw it in the trash so gave it to me. It will unlock a door but not start the engine. I have never made use of it but thought it would be a good backup for getting in the car such as when hiking or boating. As mentioned, it would be a good idea to have the real key for the car wrapped in aluminum foil so someone couldn’t break the ignition lock cylinder and drive off.
Fobs are likely going to be expensive no matter what. Getting chip keys cut can be like $10 or less depending on what you need. Some are not that simple and inexpensive but at least the ones I have dealt with are.
If you lose or break a fob that came with the car, you can still program another chip key as long as you have two around. That is why for $10 it is well worth it. The dealers charge HUNDREDS.
I paid about $80 on line for two new fobs, then about $100 for the dealer to program them. I keep one fob in the.trunk and use the other. I had a key cut that will open the door or the trunk but not start the car. Cost about $3. I tapped this key to the inside of my fuel door that is not locked. So no matter if I lose my fob or what, I can still get in.
I retract the term “valet key.” It’s a laser-cut sidewinder blade with a rudimentary head attached, NO CHIP. Therefore it cannot start the car. It’s only purpose is to open the car door so I can access the spare key that does start the car, or retrieve keys that I have inadvertently locked inside the car. It would come in handy if I were to lose my keys while hiking or drop the fob in the water while boating in a remote place where there might not even be cell service to summon help. The advantage of such a door key is that it costs a few dollars and hence you can store a few of them in various places—in and on your car, at your house, in your wallet, etc. Combined with two working fobs, this is good protection in a number of scenarios.
I do the same thing for the exact same reason. When I was cutting the chip keys, the young guy pulled a plain blank off the rack and cut it out of habit. He was going to trash it so I asked him for it. It is useless for starting the car but gets you in the door. Wrap the spare key with a chip in foil to make a faraday shield if you are worried about someone trying to steal the car.
My door key was free but the regular price on these is only like $2-3 around here. That price is for the key blank and cutting service.