Nice work Barneys! They had a segment on the last 4WDAction DVD about the new Polaris systems. They look really good.
They're actually the reason I started looking into GPS/reverse camera systems again, as I've really wanted somethign that ticks all the boxes like they do. Being a cheap bastard, I think I've almost got a similar setup for only a couple of hundred bucks. I don't doubt that the Polaris units are better quality than what I've ended up with though.
As for mounting, depends whether it's a 2-DIN in-dash system (which means you'll replace your stereo with it, assuming the Prado's have a double-din stereo opening), or if it's a standalone "portable" unit that you just suction-cup onto the windscreen.
Good luck - I'm looking forward to hearing what you think of the unit once it arrives!
Congrats!
Matto