I'm considering putting train horns ( the compressor ) in the trunk of my Savage, and the trumpets underneath. I have not heard of anyone else installing them on a sidecar rig and am wondering why not. I know they are childish, but I' never really grew up' and they are good fun so why not. Motorcycles in general are just big boys toys anyway
I think this one will fit in the trunk with room to spare.
https://www.amazon.ca/gp/product/B0BB81 ... Z0W2&psc=1
It's far from the cheapest option available, but it has quality