It’s easy to hardwire auto and motorcycle accessories with a handy 12 volt to USB cable. Instead of screwing around with cigarette lighter adapters pick up one of these special cables that drop the line voltage down to the standard USB output of 5 volts.
USB Vehicle Cable
Nowadays most everything we own can be charged with a USB cable. These vehicle cables are available with Mini USB or Micro USB terminals to fit most any Samsung, Motorola, HTC, LG phone or Garmin GPS. Most are available for under five bucks.
The only catch is sneaking the wire down through the dashboard to find a spare hot lead or the fusebox. Another handy gadget for pulling power off the fusebox is the clever Tap-A-Fuse. Available for ATO or Mini ATO-style fuses, these plug into the fusebox and provide you a new hot wire. I recommend finding the fuse for the existing accessory outlet/cigarette lighter.