Quote: and I asked for no reimbursement for instate or mid range travel (mileage or otherwise)
While you are still working, before they fire you, refusing to take mileage for your in state driving is dumber than dirt. Why would you, up till the time when you are fired for your refusal to buy a car (by the way, don't quit over this unless you have found another better job!) but anyhow, why would you voluntarily deny yourself mileage payments which they intend to give and are part of the job remibursement? They're obviously not going to let you exclude yourself from being a member of the fleet using your "clunker" car, but that does not mean you still do not have expenses from driving it or carrying the insurance in the meantime.
I once saw a supervisor try to deny mileage to an employee because they drove a motorcycle instead of a personal car. Didn't work, for unemployment purposes, anyway.
I'm not too sure they can't reasonably require a certain type of insurance to be carried by employee drivers, (is this collision insurance, high risk insurance?)but even so....
I am interested in whether or not they will go through with this, actually fire you if you refuse their order to trade up in type or age of vehicle.
What they'll strongly encourage you to do, of course, is to resign. That way they are not going to be on the hook for unemployment benefits because they have fired you for such a jerk frivilous reason. If your initial employment agreement, the conditions under which you began the job (whether or not you have a contract) was that you could use your own car, and there was no stipulation as to how old or what type of car this had to be, then you stand a good chance of drawing u.i. benefits while looking for another job if fired for this reason. Of course, in FL this is a princely sum of about $275 a week, so you're certainly in the big money, but it's better than being fired or resigning with nothing.