Looks like that one is powered by 12v too. No stepdown converter needed. I wish it came with a rearview mirror mount like the G1W-C. I am not much of a fan of suction mounts.
Can you add a pic of your Nuvicam is mounted?I gotta say I really like my Garmin NuviCam LMTHD. It records everything in 1080, has GPS coordinates and time stamps. Plus I can have a conversation with it.