How would you turn it back on again when they do pay?

Having to visit a dealership to enable the feature would cost them more in "meh, I can't be bothered" lost sales than the couple kilobytes of cellular data probably incurs.

It's a privacy concern as it is now too. I would think that if I did not pay then they would not collect the info to begin with and that's precisely why I would decline.

This is the kicker for me. If the owner didn't subscribe, Honda should not be able to locate the vehicle at all. This implies that Honda is able to track every HondaLink-capable vehicle at all times, without permission of the owner.

Are they doing anything with those data?