Behind the front bumper to the left of the badge. Hard to access, but I managed to fit 2 Hella Supertones without removing the bumper. Also the connector will need cutting off as it's a weird plastic one, get some spades crimped on there.
Its behind the front grille (or bumper on the 100hp as the grille and bumper are incorperated).
You'll probably have to relocate the horn if you upgrade is anything to different to the OEM horn, as I doubt a standard airhorn will fit in the same location, although I could well be wrong.
Am i right in thinking that a new horn would require new wiring and a fuse? or can it be a straight awap over?
I bought one for the punto and i was told it would need completely rewiring
I'd have said your better off installing a relayed circuit for it Danny just invade. You could probably easily get away with a single one but a pair might be pushing it.