Navigation Question

Hi all,

This is probably a longshot but I'll ask it anyways. Just purchased a brand new 08 Prius Package 3 a couple hours ago. I don't have a Nav system installed but I noticed that there was a Map button on my steering wheel. Is there any way I can just get the Navigation Software in CD format (since I have a 6 CD changer) and install the Nav? I'm assuming that Toyota just decided to leave the GPS receiver in Package 3 head units and all I need to do is install the necessary software for it to work. Any chance that this is possible? Aside from not having Nav, I love the Prius. I may not go head over heels on its looks, but I really like the Smart Key system and the backup camera. JBL sound system sounds good, but still inferior to the Mark Levinson system on my Lexus. I traded in my 9 month old 07 Mazda 3s Touring. Paid just over 8,500 out the door. Not a bad deal, no?

Jamie