450?! You must have got an in-dash unit or something... The sub-$100 portable units have been getting good reviews, with the only major complaint being the battery life (about 1hr if you don't keep it plugged in). I ended up getting one as I got confirmation that it will do nav/music at the same time and bt will take over if there's a call coming in (not that I plan to do a lot of talking while cagin' it - handsfree or not handsfree it's bad policy).
Bookmarks