I've told this story here before, but a while back mine malfunctioned while it was at a body shop and started calling the SOS service repeatedly. After the police called me (and came by my house the next day) I contacted the dealership and they actually sent me instructions for unplugging it. I haven't gotten around to plugging it back in, and now if I pick "customer service" in the car's menu it just gives me a 1-800 number to call. It did complain profusely the first two or three times I started the car afterwards, but it eventually gave up.

> Also it would void my warranty

No. For automobiles especially, your car's warranties aren't voided unless your modifications contributed/create a problem in the car. For Tesla, perhaps they could argue that removing the modem means they can't diagnose effectively because it's offline and not reporting any errors, but if a motor died they'd still have to fix it despite the modem being ripped out.