I haven't installed a Scorpio on a Hammer but I have on my XCT. (The Vic alarm is a scorpio) It is basically the same either way though. I installed the head unit under the left side cover, that way you have easy access to the ignition and a place to install the RF receiver under the seat.
2014 Cross Country Tour
Freedom Performance exhaust, Lloydz VFC and a Lloydz Intake/filter, Lloydz ATS.
I got the alarm mounted today. I had to move the HID ballast to behind the fuse box. The alarm fits perfectly in the HID ballast mount. I just need to make a metal strap to hold it down.
It won't fit under the left side cover, battery is there on a Hammer. Fuse box is on the right side.