It sounds like you are looking for a very clean wiring look. The cheap and easy way could be using the aux plug (cig ligher socket) with a car adapter for your GPS. I plan on using the connection from my Battery Tender and a cig ligter adapter plug and car plug to power the accesories. Not as clean as what you are thinking but functional and economic.
05 BA, Goodwood Green, Chevy605 pipes , ai removed, Freak kit, K&N pods, 145 main/42 pilot / 3 turns out, bags and screen
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