Tesla confirmed the Apple Watch app will act as a digital key, so I think it's safe to assume it will act the same as the iPhone app. Assuming that's the case, I can answer some of your questions based on my own experience:
- How often (if ever) has it failed to open the doors?
My car doesn't have UWB and relies only on Bluetooth, which isn't perfect. At least once a week it doesn't unlock the door immediately when I pull on the handle. Usually the delay is < 1 sec, where I yank the handle and it does nothing for a second and then unlocks. Not a huge deal, but not great either. I'm assuming this is why they added UWB support on newer vehicles.
- Does it use UWB to reliably open the doors when you approach and close when you leave? Or do you sometimes need to take the phone out of your pocket to unlock?
I haven't experienced UWB myself, but from what I've read it seems to be pretty reliable. I haven't come across any reports of UWB failing to unlock. Worth noting too...even with Bluetooth I never have to take the phone out to unlock when it fails. Just need to wait an extra second.
- Does it always choose the right driver profile if you have two drivers with their cell phones in the car? How does it work? UWB detects which phone entered through driver door?
This is a great question, I've never considered how it works when 2 phones are present. I did a quick search and it seems that for cars with Bluetooth, the chosen profile seems to correspond to the first phone the car connected to.
This article mentions that the addition of UWB was expected to improve the driver profile selection by detecting which phone is closer to the driver's side...but I haven't come across any feedback that confirms if this is actually the case. If anyone reading has experience with this, please share!
- Does it work with your phone if the phone if you are out of battery? (like Apple Car Key does)
I don't think so. AFAIK, this functionality is only available for apps utilizing Apple's CarKey framework, as you mentioned. The Nearby Interaction framework that leverages UWB doesn't provide any functionality that works when the phone's battery is dead.
- Should we expect all the same with Watch App (when leaving your phone at home)?
Yes I think so. Based on Tesla's announcement, I think it's safe to assume the Watch app will function more or less identically to the phone app. If you leave your phone at home, the watch will be able to communicate with the car over Bluetooth/UWB when you're in proximity to the vehicle. If you're not in proximity to the vehicle and your watch has a cellular plan or is connected to wifi, the watch app will be able to send commands through the cloud like the phone app does today.
- Are there still some benefits for Apple Car Key over Tesla's implementation?
In my opinion, absolutely. I think the main benefit is being able to use the key when the phone is dead, I've had a few cases where my phone died and I needed to start the car. Luckily I had the key card on me in all those cases, but had I not it would've been extremely frustrating. CarKey has some other nice to have features like the ability to share the key, or automatic deactivation of the key if you use Find My to put the phone in lost mode.
As much as I'd love to see Tesla implement CarKey, I'm definitely not holding my breath for it. Similar to CarPlay, as much as I'd like to have these features, I do understand why they refuse to implement them. Hopefully this changes in the future.
Just my 2¢! I'm a huge Apple+Tesla geek, and seeing my worlds collide in this article made me feel compelled to share... but I'm just a guy on the internet so take it all with a grain of salt.
