Thanks for the help guys, I finally figured out what the problem was. IT was the @#@$@ fuse. It was very hard to tell that it was blown so after carefully looking at all the fuses the problem has gone away.

 

Hey tx, if you don't mind me asking, which fuse did you replace? Was it under the hood or near the door panel? Thanks

 

I just started having the same issue this weekend and my GS powered off on the freeway this morning but came back on after a few seconds...scary. I figuered it was a grounding problem, but I heard a lot of weird noises coming from the power-steering side of the engine bay when I started it before I got on the road.

Would like to also know what fuse you changed.