You'll probably need to do at least some disassembly to get to it (maybe next time you take the car for servicing). Then you can either wrap the antenna in some aluminum foil or just cut it (which would probably fry the transmitter).
I agree, though, all our devices are becoming hostile to us.
> or just cut it (which would probably fry the transmitter).
I'd recommend physically removing the entire transmitter (the electronics can be removed with a chisel), but if you're trying to fry the transmitter, don't cut the antenna; that leaves a undamaged but low gain transmitter a la [0] (though probably not powerful enough to detect outside the vehicle). Instead, short the antenna to a power rail (or ground, but V!=0 is more likely to damage it) to fry the transmitter and also keep it from moving the antenna voltage enough to transmit anything.
I agree, though, all our devices are becoming hostile to us.