There's a whole subforum related to OBDII, have a look in there for your gauges/OBDII info. GPS and CD/MP3 are both really simple to set up. For CD playback all you need is a CD-ROM drive mounted somewhere in the car. Alot of people use a slim external "laptop" style drive connected by USB. GPS is also easy. You will need a USB GPS receiver (about $50-$100 usually) and it will need a view of the sky to work properly. Most folks mount theirs on the dash or rear package shelf right by the glass. You'll also need navigation software. Most people on here use iGuidance. Have a look in our FAQ Emporium, you'll learn alot by reading thru there and generally lurking on the board soaking up info. Enjoy!