Just get yourself a replacement horn from halfords. They still fit on the existing bracket, all you have to do is adapt the leads with 2 spade terminal connectors so they fit into the original connection port, then seal it up with hot glue. Also, you dont need to remove the whole bumper, just the left foglight panel (or just plastic panel if like me you arent lucky enough to have fogs) One more thing, if youre replacing the horn with something non-seat, make sure its not a negative-bodied horn. The first horn i tried was off a ford and as a result i went through about ten fuses!