One is in the security controller behind the cupholder, integrated with the NFC reader there. The second and third are in the Left & Right B pillars behind the cameras. On the drivers side this sits above the NFC antenna. The fourth is mounted centrally on the rear bumper beam. (Cars produced prior Nov 17 also had a fifth on the front bumper.)
I really don't want a key fob as that is just something to loose. I never lock my car and try to to never leave anything inside the car for anyone to steal anymore. I learned that when someone just smashed the window on my Porsche to steal a hundred dollar item, and $1,000 later everything was back to normal. Except I still find small glass particles when vacuuming the car. I just want to walk up to the car and go. My Lexus never fails me, same telephone.
I've had my Model 3 since Jan 2021, and I don't think I've had a problem more than once with either of my Pixel phones, a 2 and a 6. My wife's iphone 12 has had a problem 2 or 3 times, but not lately. Once or twice we had some confusion when both of us entered the car together for some reason.
My phone is set to "Optimized" battery usage for the app, which uses less battery. This is the normal setting for apps, nothing special. I'm not even sure the app settings matter. I think it's more a bluetooth issue (but that's only a guess). The app uses the internet for its control of the car, which is why it can unlock from a remote location. Simply waking up the phone might make a difference, but I never do that. However, one habit of mine that may make a difference is I restart my phone periodically. It's not that hard, and fixes weird problems. Do those of you who have problems restart your phone very often? I think all computers, especially consumer items, need to be restarted regularly. Even a Boeing 787 and an airbus model have restarts specified to fix problems (FAA orders Boeing 787 safety fix: Reboot power once in a while)
I have to say, now that we have a couple of months under our belts, that the unlock problem seems to have eased. Occasionally I need to swing my hip towards the car if it doesn't respond, but for the most part it opens right up. My Galaxy is in my pocket, her Pixel in her purse, and really you just have to have it close enough and it opens just fine. I've followed this thread and am grateful for all the input.
Geez my Pixel 6 Pro is in the living room at around 15ft and even if says locked, I can just go to the car and open the door while my phone is still in the living room. My gf Iphone 10 locks the car after just waking 3ft and I can't even unlock it until I'm 3ft of the door.
I wish I wouldn't need to disable Bluetooth every time I'm home.