Dude it's really easy, don't waste your money/time at a shop.
http://www.mazdas247.com/forum/showthread.php?t=123693832
The hard part its looking for a 12v source, but you a few to choose from.
http://www.mazdas247.com/forum/showthread.php?t=123693832
The hard part its looking for a 12v source, but you a few to choose from.