Dangerous, but hilarious (Dubai raver has set up a 303 and 606 to make acid house while he drives): https://www.youtube.com/watch?v=mwYtjQk0QaU

Interestingly, Subaru itself used to make a DCM bypass kit for its cars. When AT&T shut down its 3G network, Subaru was stuck replacing all the DCMs, because they would search and search forever for a connection to a network that no longer existed, and slowly drain the battery. But there initially wasn't enough inventory to replace them all, so they offered these bypass kits if you weren't an active Starlink (cloud svcs) subscriber.

But you do all that for privacy... and then you use CarPlay?

For this kind of thing to succeed as a general lifestyle, you would need to invest an enormous amount of time making potentially irreversible modifications to all kinds of electronic equipment - only to be virtually guaranteed to miss something.

Do this kind of thing if you want, but don't be fooled into thinking you're actually solving the problem for real.

I always though ...just need to remove the ... the antenna .. modem would always get no signal and transmissons would always fail....

Same for the GPS.

To verify- no other hiddwen transmitters could use some RF( Radio Frequency) analyzers

[RF analyzer (ie spectrum analyzer) is a tool for measuring the power, frequency, and signal strength of radio frequency signals.]