I was curious to see the Prius HUD in action; found this video on youtube and thought it was very good demonstration.
The first one was already posted at http://priuschat.com/forums/gen-iii...7405-video-hud-in-action-mkii-inc-satnav.html
The double-image in Alan's (LexVanDryver's) video is caused by reflection off the two layers of glass in the safety glass windshield (windscreen). When I get my Plug-In, I hope to eliminate the double image by using small square of window tint on the inside of the windshield. I hope I can get by with that with the police.
Prius Five or Prius Four w/ SR package. (Basically, any model/package with the Premium HDD nav is the easiest way to tell)
You sure about the Four? From Exclusive: 2012 MY Prius - Changes and Additions | PriusChat, it seems like you need to go with Five.