My Baja 540c came with the cig lighter cord too. I saw the hardwire for around 30-35 on the web at numerous sights...It does show that the power should be switched by an auxilery switch, so it may be a good idea to add you another switch to that nice dash and have it for the GPS, then cut off the end of your power cord and wire it into a fuse block/fuse to the battery. Also, are you using an aux fuseblock??
I was thinking about using a painless sealed for mine...just like my truck has...easy to install, and really solid built... Couple bucks though... OR I may use circut breakers like the race trucks/buggies use... Push the button to reset...