I think most of them are made to mount to the roll bar so unless you eith have a full top, no top, or an in-cab roll cage, there is nothing to attach it to.
The PO of mine mounted one of the cheap looking ones like you see in the JC Whitney catalog but I'm not sure how it sounds, it isn't hooked up. It just looks cheap so I'm gonna remove it whenever I get around to it. I'm not sure how it's mounted. Hopefully there won't be any screw holes to fill.