You're implying the stub of an exposed coax inside a faraday cage is capable of establishing a link with cell towers. This doesn't really pass fermi tests and I've never observed it myself, just read the paranoid concerns of people online.
replyRegardless, taping some foil around the connectors with the foil making okay contact with the metal chassis is more than enough attenuation at sub GHz microwave to remove this concern without having to source specialty terminations and crimpers (or worse, non-reversible damage to the OEM cable assemblies by repurposing their terminations). I've done the foil+tape on some of my vehicles, but it hasn't made a difference in binary "does it connect or not?" testing.
Best to use a termination, to avoid the power that would have gone into the antenna from reflecting back into the transmitter output and damaging the output driver transistors. Damage is no bad thing if you do want to permanently disable the transmitter, but not so good if you want it to be reversible. Chances of damage due to reflections is probably low given the relatively low power being transmitted, but best not to take the risk if it can easily be avoided with a termination.
replyI agree it's a good practice. However in this case I consider the possibility of frying the amplifier a knock-on benefit. The fucking thing should have never been made.
replyIf a hypothetical future owner feels strongly about it then replacing a telematics module in the dash is much easier than replacing harness runs. I somehow doubt I would sell one of my vehicles to someone who would do that though.