I would likely agree but curious, why exactly do you not want the GSM chip in the car and what would lost by not having it?

These chips broadcast cards location back to Hyundai as part of a paid program to see where your car is on your phone. What is Hyundai's data retention policy? Their data security? If it's anywhere near as poorly thought out as their in-car UX, that's pretty scary. I'm sure they'd bend over backwards to law enforcement request of data.

It could be doing OTA firmware updates for example.

Isn't it also telling the GSM network where the car is? (Could be a feature of course, but of course also very problematic.)

You could simply remove it? Or does it fail to start when the car can't reach the cell network?

Likely depends of the source of the GSM; some cars are sold with OnStar, LoJack, etc. - and have anti-tamper feature and/or remote kill switch. It's my understanding that OnStar can even kill the car while it's in motion, which seems a bit over the top if you ask me.

oh yeah, marketed as "anti theft" but scared to know exactly how hard this would be for some bad actor to crack :/

It's possible that the GSM chip working is a part of the immobilizer system: https://en.wikipedia.org/wiki/Immobiliser