When '60s and '70s Cadillacs were plentiful in junk yards, I made a side gig from pulling the quad-tone horn setups in those cars (notes were A, C, D, F, sounded like a train). I cleaned up the horns, made dual relay harnesses and sold the kits to people who complained that nobody heard their horns.
My wife came home upset that she honked at someone in her Honda CRV and they didn't hear her. So I put my last set of Cadillacs in her car. Sounds awesome and commands respect. If you can find an early 90s Buick Park Avenue or Olds 98 in a yard, some of them still have four-horn setups.