Just because you can do something doesn't mean that you necessarily should. Hence the curious lack of venison-flavored gum with an appletini-and-wasabi center. The same goes for technology as well. There's a vast array of incredible things that we're capable of, technologically, but not all of those things make sense. Proximity keys for cars are one of those things.
Just to be clear, when I talk about "proximity keys" I'm referring to a very popular feature on many new cars — keyless entry and ignition systems, where a small fob that is carried somewhere on or in your person communicates via radio waves with your car to open doors, start the motor, etc. In some ways, it's remarkable technology that my grandfather would pretty much have thought was magic. You approach the car, and it unlocks. You sit down, the car and key hold secret almost-instantaneous negotiations through your pants, and you're able to start the car and drive off. Easy!
While it absolutely is easy, I feel like the novelty of the technology has blinded carmakers from really thinking through the real-world use and utility of the tech. The problems aren't technical — the systems almost always seem to work well — it's a fundamental conceptual problem that has to do with our relationship to locks and keys.
Let me give some examples. I reviewed the Hyundai Veloster Turbo last year, and it uses a proximity key system. I was there with a bunch of other journalists, in many Veloster Turbos, on a road course with several stops. At some of the stops we'd switch between manual and automatic cars, etc. The proximity keys were either left in the cars or in a driver's pocket, like you would in real life. A surprising number of times journalists would forget they had the key and leave the car for another, or get in another running car that had no key at all. What happened was you could be driving in a car with no key, or the wrong key, and all would be fine until you turned the car off and found yourself unable to turn it on again.
Also, this week I've had a press car with a proximity key. My wife clipped the key to her bag and took it for a spin. While driving, the clip holding the key on her bag sneakily failed, dropping the proximity key under the seat. She then couldn't find the key, and had no idea if it was still in the car or not. That put her in a situation you could never be in without proximity keys: losing your car keys in mid-drive.
Plus, many times when we were driving together, one of us would leave the car with the keys in our pocket, stranding the other. There was less pressure to know where the key was at any given time, and that caused multiple issues.
Proximity keys get rid of all the routine of keys, and trade that for a new, less useful routine. With proximity keys, you still have to find and push an "engine start" button, which, as far as physical actions go, isn't that different than turning an ignition key. I'm not luxuriating in all my newfound spare time since I don't have to place a key in a slot.
Having the car automatically unlock when you approach with the key is very useful, sure, but when it comes to starting I think its important to make physical contact with the car and key. Some proximity-type keys do this — Mini, for example, has you place the fob in a dash slot, which is really the same thing as using a key, so it works to solve these issues.
The basic problem here is that proximity keys break the cause/effect cycle of locks and keys that we've known for centuries. Key makes contact with lock, lock opens. Breaking this in some contexts makes sense, like when the key is in your pocket and you're running to your car chased by zombie clowns. You want that door to open automatically. This works because either you have the key, and the door opens, or you don't and it doesn't. All the possible results are the same as if you had a physical key.
But for starting and running the car, there's a fundamental change to the system. Physical keys require a constant contact to keep the car running; proximity keys only require momentary communication. And that's the issue. Old keys had a place they had to be to make the car run, so worrying about where the key was or who had it isn't an issue — it was where it's supposed to be, or no running car for you.
Proximity keys give you the freedom to not know where the hell your keys are while you're driving, and that's a freedom I think I can live without. The act of placing a car key into the car's ignition slot and turning the car on has never been an unpleasant act for me, anyway, and it's more of a pain to figure out what to do with the remote fob, when you're driving, anyway. It usually has to come out of your pocket at some point open a trunk or lock the car or something.
There are solutions here. The ultimate one that would solve proximity key's issues would be to just go all the way and implant the damn thing. You'd give up a molar or have a weird lump under your arm or something and you'd never lose your keys again. You'd just need surgery every time you got a new car, and you'd need some valet key or something to avoid painful parking-lot surgeries. Maybe that's not such a hot idea.
Other than implanted keys, the proximity key could require a constant handshake to keep the car running, so if someone accidentally walks out with your keys, the car will stop, and you'll know.
Or, just put the damn key in the dash, already. Really, it's not that big a deal.