I just relocated mine and I have a coupe. What I did was i ran my negative wire down to under the back seat. backed of of the seat belt bolts out and put the ground under there and tightened it back up. no problems so far.
im planning on running mine under the car, maybe try to run it through the frame, is thats goin to be possible... Im just goin to connect the positive back to where its mounted now, which doesnt seem to be right to the solenoid, maybe theres another wire that goes there?