I am looking at finally integrating GPS into my car. Although it already has a GPS receiver for the unused OnStar system, I will have to install another. OnStar is only installed in American Saabs, so documentation is nowhere to be found.

I have been looking at this garmin unit. I will likely mount it in the glove compartment and have an antenna running from there to either the windshield or under the hood. Any comments? That thing looks like it's going to cost $100.

I will need an antenna. I have an 8db WiFi (2.4GHz) antenna doing nothing. Will I be able to use it as a GPS antenna? If it can be used, will I be able to get a signal under my car's hood? I think it should, but I am not positive.

Also, what are the characterisics of the empeg's serial port power? Will I be able to power the reciver off the serial port? Here's the voltages it can use:

60 mA @ 8 Vdc peak current
50 mA @ 8 Vdc nominal current
40 mA @ 12 Vdc peak current
33 mA @ 12 Vdc nominal current
15 mA @ 40 Vdc peak current
12 mA @ 40 Vdc nominal current
100 mA from 3.3 to 5 Vdc peak current
85 mA from 3.3 to 5 Vdc nominal current

Thanks!