... after reading all the above, I see no one has hit on the Low Tech solution that can done with every Tesla.
The answer is very simple.
Turn off Sentry Mode and then Alarm Mode after you stop and before you start your Nap.
A quick and painless fix, and something takes about 5 seconds to do at the start of your Nap and about 5 seconds to undo After you start the car at the completion of your Nap. Do start the car 1st, to let it know you are there, before you reactivate Alarm, then Sentry Mode.
I do this when ever I leave passengers in the car whilst I visit an ATM or do other quick out and back, drop off, pick up chores.
With other cars, it has been my experience that there are two ways to stop the car alarm from screaming if you stop for a Nap.
One... leave the key in the ignition works for some.
Two... putting the car into Valet mode whilst you have your Nap is another.
There is No need to invest in fancy detector upgrades if one is willing to do preventive thinking and solve a problem before it starts.
Food for thought,
Cheers, Hugh-SG