I've done horn upgrades. Plug and play is not totally accurate. It depends on the current draw of the new horns.
If you're gonna upgrade for more audible output, install a pair of quality horns of your choosing. You need some basic wiring skills or a buddy who can do it for you. Wire the 2 horns to a 30 amp 5 pin generic SPST relay with a 20amp fuse to the battery positive. Run the factory horn wire to the rlay coil. Ground the other side of the relay coil to the car frame. Ground each new horn to the car frame with a separate wire if needed. You'll end up with loud horns that are reliable, fuse protected, and you won't damage any factory wiring due to excessive current draw.