You could remove the SIM card (if there is one), remove the antennas, pry off the modem, run a cell jammer (only for driving in Antarctica!), drive it in the mi

You could remove the SIM card (if there is one), remove the antennas, pry off the modem, run a cell jammer (only for driving in Antarctica!), drive it in the middle of nowhere, DOS them via your free network connection until they boot you off (and hopefully they don't brick your car), etc...