Kenwood remote speaker headrest bracket

I mounted a Kenwood TM-V71A ham radio in my Fiat 500, which as you know has no room whatsoever for things like a remote speaker. I came up with this bracket that bolts to the sides of the speaker and allows the seat headrest pipes to ride through them.

Specific details so you can decide whether these will work for you:

* This Kenwood KES-3 speaker is 112mm wide at the bolt holes on the sides.
* The headrest poles on my car are 14mm in diameter; I made the bracket holes 14.75mm.
* The headrest poles are 150mm apart (center-to-center).