I know your plight since I am in the outerboroughs a lot and see lack of parking. Many people get the ugly bumper buddies. Some have the auto armor.
I saw a commercial for the bumper step which can be removed when you sell the vehicle or if you are in the burbs. It does require a trailer hitch though.
For those who wonder what the bumper buddy or auto armor is, here are pics
Bumper buddy / bully: