I've seen around Sydney a grey VT Commode with the same treatment - a wagon with the rear end cut down into a tray-back, and the cabin ending behind the rear seats. Funny looking thing, made me look twice. Don't know who does the conversions, but it looked a pretty good job. I assume you'd be able to do the same thing with the Falcon too.
The HSV...may not visually mirror the HRT cars, but it is a statement. Then again, so is 'I'm trying too hard'.