Haha definitely get one for cabbies.
I've been thinking of hanging a bright red and blue reflector off the back. Makes me look like a cop at a quick glance, they're passive so I think the colors might be legal as long as they're not flashers.
Crazy cabbies, watch out for buses and trucks, they can't see you in their huge blind spots.
Watch out for opening doors on the right from parked cars AND on the left from cabs letting passengers off.
Make liberal use of the middle finger