Well if you could do a lil more then the 500 mark you could do a whole PC. Would still need navagation software but in my opinion it hands down the better value.

I think i sank about 700 into my carputer. Thats with medium range options, not the most $$ but not the least either.

And with a PC your multimedia, nav and all other stuff is covered.

And if you do some digging and mp3car.com Ud be amazed.

Still need GPS software... ebay cheap like 40 - 60 for MS Streets