He flinches as it hits the car, staring at it as the glob sides down and begins to burn through it. The car alarm starts to go off and he winces again at the noise, eyes flitting up and around at the buildings. Another glob sails close and he startles, throws himself sideways to grab for the metal bin. It brushes his shoulder and he curses, begins frantically shrugging off the jacket and throwing it aside before the stuff burns through to his skin. The black jacket sizzles and he pulls the lid off the bin, sheathes his dagger and grabs the empty body of the bin too.

Right. Time to go to battle with a dustbin. Adopt, adapt and improve etc.

He hauls it around and wields the lid like a shield -- grabs the edge of the container and runs at it. Maybe he can ram the dustbin over the horrible thing's head. That sounds satisfying, and would buy him time until it burns through.