Hey Grant - I have a suggestion. Get a small enclosed trailer and put your stuff in that. If the cabs don't have a trailer hitch pay the cab company if you have to for them to install one. Everyone benefits, the cab company spends less time for the same fare, and you save time by not having to load and unload every single item at each stop.
They would install the receiver hitch,
but you would provide the ball and mount
So they wouldn't have anything hanging out during their normal runs. What do you think?