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This is exactly what I do on vacations.
This is a bigger concern than losing phone and not having the key with you for the car.
If that happens, you can just take an uber home and get your fob. If I was going out of town, I’d definitely take my fob ; but for short trips near home having this feature would be great.
I suppose for me Apple Watch comes in handy too - it's like double protection. I don't have car that can use the key but if both your watch and your phone can do it with UWB that's at least double the resliance of just having a key would usually be.

I do have an EV though and there's been a couple of times in 8 years where it's been handy to have an app to unlock it. I remember in the past many times people locking their key in their own car. In fact that happened to me once around 2009 - I shut it in the boot (trunk) and roadside assistance had to come out with a magnet on a long pole. Thankfully those mistakes can't be made so easily anymore!
 
Ah, but then you just lose your car keys and you can use your phone to call someone to pick you up or bring you spare keys.

But if it's all on one device, you lose access to everything.

Many people don't even carry a wallet anymore, since all their cards are on their phone.

As are all your passwords, messages, emails, etc.

What I am saying that the more eggs put into one basket, the more catastrophic it becomes to lose access to it.

What I am not saying is that Apple or Audi shouldn't do this, because it's an added convenience to be able to use your phone as a Swiss army knife.

I'm just pointing out the inherent downside of this, as I don't think there's enough awareness around this.
I will say that the MyBMW app - and likely others who support this Apple feature - has the ability to invalidate issued digital key grants. It is a hassle if you lose your phone but you're already in a long checklist of hassles so what's one more? ;)
 
maybe you're confused because you don't know what systems design is or understand the importance of avoiding single points of failure?
I’m confused as nobody is forcing you to use Apple Pay, Car Key etc.

If anyone wants to do that and is aware of the risks, then fine.

Call out the risks (which educated users would know, certainly anyone on this forum would know), but why is it seemingly your mission to warn “EVERYONE” what they need to be aware of.
 
This is great, but it sure seems like putting all our proverbial eggs (car keys, driver's license, bank security codes, etc) in one basket (the phone) creates a single, potentially disastrous point of failure.

Lose or break your phone and all of a sudden you are an outsider to your life, locked out

It's not a singe point of failure. Cars that use phone-as-key invariably also come with a physical key or key-card, which you can keep in your wallet or a safe place. You can also have keys on additional devices (like Apple Watch), or assign keys to trusted family members, etc, so you have them on more than one phone.
 
It's not a singe point of failure. Cars that use phone-as-key invariably also come with a physical key or key-card, which you can keep in your wallet or a safe place. You can also have keys on additional devices (like Apple Watch), or assign keys to trusted family members, etc, so you have them on more than one phone.

I was referring to the phone as a single point of failure
 
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