I'm not into this infrad sensor. Living in a city where parallel parking is a part of everyday life, you need to know how many inches are behind you. In every car I've had I could always sense how much space, but the H2 is too big and the bumper is high enough to damage grills.
I think a good feature to add that costs nothing is the wide-angel rear window lens.
Here's one on ebay for under $5. THere's another thread on this on the forum.
For Mac it is simply a sign hanging from his front visor that says "Look when you back up Sherlock". [img]/infopop/emoticons/icon_biggrin.gif[/img]