Had a couple of late-night near misses towing home from race meetings with (mostly foreign) artics drifting across lanes .... presumably they'd been driving through a few countries to position their tired carcasses in the path of my camper!

I got a pair of Russian truck-horns with associated compressor ... cheap as chips off ebay ... they sound like the last trumpeting of Angels at Armageddon (more like a US freight train than a road vehicle) .... ran them off the existing horn push through a relay .. because the compressor takes half a second to spool up you can give a quick polite toot of the old horn (sometimes useful) but if you hold the button a smidge longer it's WW3 🙂

Sure to wake even the most dozy midnight trucker.

Only issue may be finding a suitable unused space under the bonnet.

K