cost is actual not an issue..... all together I have $1325 in the project including navi software maps a copy of XP home and the gps satelite receiver, XM PCR w/antenna, a 100 watt Alpine V power amp to carry the signal to the stock crossover and a 555 delay timer for the power up of the amp so I don't hear any boot up noises during the first 40 seconds of boot up.... Got the DC-DC converter inside the pc w/ ITPS for motherboard control power and volt regulation so when I turn off the car the computer powers down like I went to the start menu to power down... really slick.... When I turn the key to accesories or behyond the computer will power up. Just like a normal OEM powered accesory.

All the info and more is on mp3car.com forums that place is a mecca for this kind of stuff. plus it helps having an engineering background (3 years in engineering until I saw the light and switched majors) I knew I would be a good engineer but it was just that I had to work with other engineers that changed my decision