So, I finally decided to try the key to open the door in case the battery was dead, or the FOB went dead. It was hard to turn, but I finally got it done, but the alarm went off and I had to turn it off with the FOB. How can you stop the alarm without the FOB in hand?

 

Since you can't start the car with just the key, probably the only way is to pop the trunk open and undo the positive or negative cable to the battery. You will have to reset the windows if you have a convertible after the dust has settled...

 

Would you have the physical key without the fob, since it’s stored inside the fob? I think it’s intended to be used when the car’s battery is dead, or the key fob’s is.

 

if the battery is dead, how do you open the trunk (2017 convertible)

 

Get in the car and pop the hood, then attach 12V to the underhood terminals. So long as the battery isn't actually faulty (or disconnected!) you should be able to open the trunk.

 

From the 2021 iguide it says: To unlock, turn the key blade clockwise and release. The alarm sounds if the door is unlocked until the smart key is positioned correctly to disarm the alarm. The alarm also sounds if the unlock button is pressed on the smart key
I expect it would be the same in other years but I'm not sure what "positioned correctly" means

 

There’s a spot under the dash you can place it if the fob battery is dead, and it will then let you start the car.

 

Yes, the seldom-used mechanical lock cylinder can become quite stiff...and it is possible that the inside 'mechanism' isn't engaged enough to deactivate the alarm.

We 'exercise' our mechanical lock once a year, and apply a graphite lubricant like Lock-Ease.

I exercise it in the garage however, and the car isn't locked.