Second on the Caddy horns. Just go to the yard and pull them from an old Eldo or Fleetwood (older the better)

I did this for both the Subaru and the BMW

Here is a tip, take the original horn wiring and put them through a heavy duty relay and then run a large wire from the battery to the relay to the horns.
The wiring on the Japanese cars cannot handle the load a set of big DEEETROIT horns puts on it.

__________________
"I have no convictions ... I blow with the wind, and the prevailing wind happens to be from Vichy"

Current
Monika '74 450 SL
BrownHilda '79 280SL
FoxyCleopatra '99 Chevy Suburban
Scarlett 2014 Jeep Cherokee
Krystal 2004 Volvo S60
Gone
'74 Jeep CJ5
'97 Jeep ZJ Laredo
Rudolf ‘86 300SDL
Bruno '81 300SD
Fritzi '84 BMW
'92 Subaru
'96 Impala SS
'71 Buick GS conv
'67 GTO conv
'63 Corvair conv
'57 Nomad