You know how there's the bird's mouth lookin kitchen tool you use to poke triangles in juice cans? Usually the other end of a bottle opener. Do that twice on the top and twice on the bottom with the holes lining up. Thread plastic zip ties through the can and attach somewhere. Just attach to the framing itself or whatever looks best. One zip tie leaves it rattling and found sooner than you want. Yeah, it's messy, but worth it. A lot of oil goes just in the installment, but plenty stays. Tuna works, but I'm sure anything meat based and in a can would rock his world as well. I haven't done this in a city. I imagine hordes of alley cats being attracted, reproducing and fighting all over the car.