It looks like a channel mount for the hood. Open your hood and there should be a way to mount it with machine screws to the metal just under the hood, and still be able to close it. There may even be existing bolts there that you could use to mount it.
The only thing is, the part where the antenna attaches needs to be on the opposite side of the mount so the hood can open. If it came assembled like that, it may be intended to be mounted elsewhere.