I’m not sure what you’re looking for. I feel like we’ve reached the point in the conversation where no perspective but your own is correct.wait a minute: so you, as a supervisor, would be ok with each person having a key, and a 3rd key being in the truck with the engine running, and the doors unlocked?
Once thing I have learned in all my time of employment (both in fire and ems and in corporate world) is that if you don't ask for something, the odds are very low of you getting what you want. This is especially true when management doesn't know what the field staff want, or hasn't ridden a truck in a while.
And no, I am not saying go into the directors office and demand change; however, if you walk into the director's office and say "hey mr director, why don't we have kills switches in our trucks? ambulance get stolen (and here are several examples), and we don't want to end up on that list. and if we turn off our trucks, they might not start up / the meds might go bad / the truck will be too hot or cold for our patients. Is there a reason why we don't, other than 'well, we have never needed them before, so why do we need them now?' or simply because no one has ever asked for them beforehand?" he director might say "well, we don't have it in the budget for this year, but maybe we can get them during the next fiscal year."
It's 2019; I would have thought this security issue was handled post 9/11 among the majority of 911 ambulances..... apparently I was wrong.