Fiamm air horns and a e39 touring

[peterzoom]

I have been given a set of air horns today. Complete with relay, compressor and assorted brackets for the twin horns. I quite fancy fitting them to the Touring ( I already have a set on the Z3)
Two questions really.......
1. Are they really appropriate for a 5 series Touring?
2. Any, model specific ( 2000 520i), recomendations for sourcing a suitable live feed without resorting to long cable runs?