No, my car wasn't keyed. The keys are the problem. Or maybe it's just some kind of obsessive overreaction on my part. You be the judge.
My new Acura has a keyless entry system. That means the car has proximity sensors in the doors and the trunk that sense and react when the key is near. So if I have the key in my pocket all I need to do is touch the inside of the door handle and the door unlocks. Then, once seated in the driver seat, I can just press a button on the dash and the car starts. I never have to take my key out of my pocket, or if I were a woman, I would presumably never have to take my key out of my purse. Nifty.
It goes further. You get two keys (labelled 1 and 2) and the car knows which key was used to open it. Each key can have specific radio presets and seat positions, so if you have two drivers the car automatically sets itself up correctly for whoever is driving the car. I don't have two drivers but I can see where that would be useful.
Here's the problem. You can only have two keys at once, ever. You get one key 1 and one key 2. That's it -- no backups. You can get a replacement key but it must be programmed to be either key 1 or key 2 and once it is programmed the previous key 1 or key 2 no longer will work. You will only ever have two keys in existence that will start the car. There is no old fashioned key back-up that you can keep in your wallet (which is what I have done for decades). If you are hundreds of miles from home and you lose your key your car becomes a $30,000 dollar brick. You have to make arrangements to get it to the nearest Acura dealer or you have to make arrangements to get home and get your backup key. A replacement key itself along with the programming of it will run you about $400. Couple that with whatever transportation arrangements you have to make for yourself and/or the car and you are looking a four figures for a lost key. Yeeow!
You ask: Why not just keep both keys with you? Possible. These are big fat key fobs. It would be almost like carrying an extra cell phone everywhere. Also, you would have to take the time to program the car identically for both keys or it would be confused about where to set the drivers seat and the radio presets. Do-able but annoying as hell.
You ask: Can you hide the spare key somewhere on the car in one of those magnetic boxes? Maybe. But remember the proximity sensors will simply open the car if a key is near. So that would be risky.