What would you do?

A neighbor in my building has had their car parked on the street outside for at least a year. It never moves and I’m convinced there is a dead animal under there bc it smells like literal shit every time I walk by it (which is everyday! Bc it’s right infront of our building). There is a mound of dirt, garbage, and sewage piling up under the car since the sweepers never get to it.

I want to call the city about it but my neighbor is extremely aggressive and rude so I don’t want them to know it was me, I don’t want to have any tension as we live so close to each other.

Is there a way to anonymously report the car without it getting back to my neighbor? What would you do?