Stereo & Electronics - Where to Find a Power Wire for Lighting

I'm adding a light bar *SOMEWHERE* on my car, and I need a 12V power wire somewhere inside to run to a switch. Any good places to grab some power from?

Thanks

Check here!
http://www.the12volt.com/installbay/vehiclewiring/1/yeard/Pontiac.html

So, i'm gonna need some wire taps huh, lol.